Another location to consider...
Marion, GA, the geographical center of Georgia. Don't know what else is there to see and/or do but it would be unique.
IMHO...a state park with shelter and fire ring would work quite well for Mike's proposal. Here is link to the
Georgia State Parks map. Looking at the map, High Falls looks to be sorta centralized, has reservable group shelters but that is all I know about that park. Melanie and I have stayed at several in the northern mountains but don't see those as viable draw to include the entire state.
Is it time to say there are multiple subsets of Georgia Spyder Riders?