Whatup Ukeninama and CampbellSoup,
I'm a resident going on three years in the ATL and my girlfriend bought me my first uke (a Bushman Jenny) at Maple Street Guitars, which is in or around Buckhead (I'm bad with directions). Buckhead is just north of Downtown Atlanta. Maple Street is the best acoustic instrument shop I've found in Atlanta; they regularly carry Bushmans and a few other varieties of ukes. I'd call them in advance and see if they've got something you might be interested in. In terms of other stores that carry ukes, I'm afraid I haven't found many. Midtown music is great for guitars, but doesn't carry ukes. Guitar Center carries some Cordoba ukuleles from time to time, but I've yet to play one that was setup properly. Earthshaking Music over in East Atlanta reportedly carries ukes, but I haven't been by there yet to see what they actually have in stock. Same deal with Sandy Springs Music, which is on Roswell Road I think. I think your best bet is to try Maple Street and go from there.
Good luck on your uke hunt and I hope you have a great stay in the ATL! This city has really grown on me since I moved here.
Best regards,
David