I'd have thought Florence (AL) would have a bike shop, but since I've never looked for one when I went through, I don't know for sure.

My suggestion: ROAD TRIP!!! Plan for a day (or long afternoon) in your choice of Nashville or Memphis. Look up bike shops in the area the week before you go, call around and ask what they have that might work for you. Spend some time visiting multiple shops, test riding as many bikes as you can, and making notes. Around 3:30, go buy the bike that's been calling your name, buy whatever necessities you don't already have (lock, spare tube, pump, panniers, water bottle and cage, etc.). If you're going to get panniers, buy them and ask the shop to install them -- they're either trivial or enough to make a seasoned mechanic swear, usually the latter. Enjoy a nice dinner, and head home.

Are you close enough to head over to the Natchez Trace on weekends? Some nice riding there!