I've used Ronnies Automatic Transmission Service a few times and referred a few of my buddies to them and have nothing but good luck! the guys there are nice and they really know their stuff! also resonable on pricing! they are on the south side but they are the only place i know of close to atlanta!
Bob (owner) of Thurmans shop has been the only shop we've used since we moved down here in 89. I've had my E40D gone thru by them that is in my 94 Lightning. They've also done several C6's for us as well. I wouldn't go anywhere else for a quality/warranty'd rebuild.
102 Mann Blvd
Stockbridge, GA 30281
The folks at Garmonds are great people too, we have dyno'd several vehicles when they had the portable there. I've also had some small machine work jobs done there with excellent results. I didn't know they rebuilt transmissions though, I thought that stuff went right down the block to McDonough Transmission.