I live in North GA so I might be able to help you out. Dukes Creek is my favorite stream in the state. It is the best public trophy stream in Georgia in my opinion. Small stream loaded with fish. It has a reputation of being tough. The fish are stream-born, so there not big dumb stockers. My first trip there I landed 3 bows over 20" on a size 22 midge pattern. It is only open for fishing on Wed, Saturday, and Sunday. You also have to make reservations, but there is no fee to fish. You have the Toccoa River in Blue Ridge which is an excellent tailwater fishery, and Helen (where Dukes is at) isnt too far away. Both these areas are pretty close to the Dahlonaga. Both areas have more to offer, those are just my favorites. Not real sure as far as camping goes. North Georgia Trout Online is a good site with loads of info. Some of those guys have some great information on camping, hiking, and fishing.
Hoped some of this helps out. Good luck!