Our Team

Tim Thornberry
MBA®, ChFC®
Partner, Cornerstone Financial Partners, LLC
Tim believes better conversations are the foundation of financial planning and advice. Better conversations have the power to connect families, trusts/estates and businesses to a more meaningful plan. Tim leads the company's business succession and executive compensation planning efforts. He is still passionate about helping families and believes individual financial goals are the backbone of everything that we do at Cornerstone.
Tim has a MBA from the Terry College of Business at The University of Georgia and holds the Chartered Financial Consultant (ChFC®) designation from the American College.
Tim and his wife, Brittany, have six children: Alexander, Lucy, Carson, Connell, Levi and Caroline. A Marine who deployed twice, Tim is supportive of veteran initiatives and serves on the boards of The Enterline Foundation and Hi Hope Service Center. In his free time, Tim enjoys golf, basketball and layering in a bit of travel.
Tony DiMatteo
Partner, Cornerstone Financial Partners, LLC
Tony thrives on helping people financially navigate through their seasons of life. In addition to his work with individuals in goals-based financial planning and investment advice, his role in the firm emphasizes business planning for owners and key staff. After graduating from Rutgers with a triple major, Tony embarked on a career in technology engineering and development. Tony had leadership roles in companies ranging from startups to Fortune 500 firms. He has also owned and operated several businesses. Tony has clients across the country and splits his time between Charleston, SC and Johns Creek, GA.
Tony has raised two daughters , Nicole, who is a nurse, and Nina, who is in hotel management. Tony serves on the Board of Creative Enterprises, a non-profit training and employment rehabilitation program for adults with disabilities. Together with his wife Roxane, they advocate and support animal rescue. They have rescued and rehabilitated several abused dogs, each with a unique and inspiring story. They have been featured on Fox 24 news and the cover of Low Country Dog magazine. They both love the water and can be found boating most weekends. Fun fact: Tony is an aspiring writer and hopes to have a novel published one day.
Michael Steck
CLU®
Partner, Cornerstone Financial Partners, LLC
Mike, after 38 years of experience in Financial Services, he continues to look forward each day to studying the influences on the financial environment and guiding clients toward realizing their aspirations.
A graduate of the College of Business Administration at St. John’s University, Mike began his career in retail executive management with Federated Department Stores. Participating in the management of a 585,000 square foot department store was a thrilling experience. However, with a background in economics and a deep-rooted dedication to finance, he made a career change that he continues to value. He recently merged his business with Cornerstone and is excited to join the dynamic group as a Partner.
With a lifelong passion for baseball—having played through college—Mike has enjoyed the game vicariously by coaching at the youth level for many rewarding years. These days, he never misses an opportunity for a tennis match.
Giving back has always been important to him. For the past 18 years, he has been actively involved with St. Jude Children’s Research Hospital, participating in fundraising and awareness campaigns, inspired by his wife, Salli LeVan, who serves on the Board of Directors. He is also a supporter of Year Up, an organization that provides opportunities for disadvantaged young adults, and has contributed by offering seminars in basic money management.
Amanda Lieble
Partner
Amanda leads operations and strategic development at Cornerstone, working closely with the firm’s most complex client relationships. She is central to how the firm runs, and to the culture and leadership that will define Cornerstone’s next chapter. Amanda brings a rare combination of deep perspective and genuine care — the kind our clients remember.
A Western Governors University graduate, Amanda is driven by curiosity and a quiet commitment to continuous improvement. She is married to Charles and is the mother of three daughters. Outside the office, she is most at home with family, a good book, and an occasional trip to Paris. A love of Paris has grown into a deeper passion for travel and new experiences — one she shares with her three daughters as the years unfold.
Brandon Chia
Investment Consultant
Brandon is an Investment Consultant committed to advancing financial literacy. He supports clients through portfolio analysis and helps them align with long-term objectives. An optimized portfolio creates confidence that flows throughout one’s financial plan.
Holding an MBA from the University of Georgia, Brandon brings a strong grasp of macro and microeconomic trends and their influence on market dynamics. His approach integrates portfolio construction, tax-efficient strategies, and risk management to deliver tailored financial solutions.
Brandon is happily married to his wife, Sandy. Together, they enjoy traveling, exploring new cultures, and discovering great food. He’s an avid hiker and loves spending time with his three dogs—Moose, Nugget, and Milo.
Will Gillett
CLU®
Financial Planner
Will has a passion for helping others navigate life’s unscripted personal and financial challenges.He believes the success of one’s financial plan relies on a personalized approach to protecting, growing, and the prudent transfer of wealth between generations of clients.
Will serves on Dunwoody High School’s Academy of Finance board mentoring juniors and seniors. He regularly speaks to them about entrepreneurship and personal finance. Additionally, during the fall you can find Will head coaching a 10/11U football team at Murphey Candler Park. For him, it’s a blessing to mentor young men at the same park that gave him lifelong friends, memories, and the framework to excel in his business. When not volunteering or working with clients, you can find Will running, spending time outside with his dog, Cash, hosting friends at his home in Dunwoody, and cheering on his alma mater the Georgia Bulldogs.
Ryan Tennant
Financial Advisor
Ryan began his career with Prudential in 2020, driven by a genuine commitment to helping clients achieve success in retirement and reach their financial goals. He’s a proud graduate of the University of Georgia and a passionate supporter of its football and baseball programs.
Outside of the office, Ryan is deeply involved in his community, volunteering as a youth baseball coach with NYO Bronco at Chastain Park. He finds joy in mentoring young athletes and fostering teamwork and confidence both on and off the field.
A lifelong learner, Ryan enjoys reading and playing trivia games to keep his mind sharp. When he’s not working or coaching, you’ll likely find him at a ball game or spending quality time with friends and family.
Ryan brings the same energy, dedication, and team spirit to his clients that he does to the sports and communities he loves.
Luke Hedrick
Financial Planner
Luke has been with Prudential Advisors for 6 years, working jointly with our team increasingly over the last 3 years. Before working at Prudential Advisors, he worked as an engineer out in the field. Working through difficult environments gave Luke a strong work ethic and resiliency. He has built quality relationships with engineering and construction companies and employees given his knowledge from the industry. While Luke brings value from his technical background as a former mechanical engineer, his empathy and personality are what sets him apart. He enjoys helping families and business throughout their financial planning journey whatever stage they may be in. He is a great problem solver and is seeks to find the path to achieving your financial goals even when it seems overwhelming and complicated.
Outside of work, Luke is a big Atlanta United sports fan along with many other Atlanta sports teams. He enjoys spending time with his family, friends, and most recently, his son. He enjoys doing anything outside and specifically being out on water: lake, ocean, river, pool, etc. He is excited to join the team and continue growing as a financial advisor and planner on our team.
