@Megan Shelton, glad you're considering jumping into the Chattanooga investment scene! Definitely set some key word alerts (if you haven't already) for the area. Chattanooga, Red Bank, Cleveland TN, Northshore, Highland Park, 37404, 37415, Hixson, and 37409 are all potentially useful, depending on what you're looking for.
My wife and I are also out state (actually out of country) investors, and we faced the EXACT same challenge. We had money to spend, and we couldn't get realtors to call us back.
@Thomas DeMoss (who posted above) definitely works with out of state buyers (he works with us), and is very responsive and great with the technology necessary to work with investors from a distance. I don't want to put him on the hook for your upcoming trip, but if he has time, it would be worth reaching out to him. He's an investor himself, so he knows the deal.
Send me a colleague request if you want. I'd be happy to talk about some of our challenges, and successes, investing in Chattanooga from a distance.
Beyond a realtor, let me know if you'd like to talk to a property manager or local accountant. We have both and are happy with each.
Good luck!