You do not want to go up there the last weekend of this month! The annual 6 gap ride will going on September 27. You'll have thousands of bikes traveling 104 miles over and around the mountains lol!

Camping at DeSoto Falls is the most logical thing to do. It's paved, plenty of parking, and resources are close. http://www.fs.fed.us/conf/desotocp.htm You can camp at Vogel but it's only 1 or 2 tents per spot with a max number of people and cars. Not sure what the exact rules are at DeSoto.

Honestly I'd go to the spot that's in the turn right below the cliff on Richard B. Russell (Hwy. 348). Parking, campfire, and tents right there on the edge of the road and I don't think there are any rules or fees.