Worth Co. and Warwick are a couple of good places. If you dive.....the Flint River in Albany is another good place. I know some divers....they said they saw catfish bigger than they where.
Have heard of people finding them all along the Conasauga River in Murray and Whitfield Counties. Johns Mountain Area in Walker/Floyd County. Tunnel Hill/ Rocky Face Area in Whitfield County.
Just walking along the banks of any of the bigger rivers might produce some good finds, especially with the water levels being down due to the drought, just look out for bad snakes. I've found heads all over the state. I would also ask around to some of the older folks in your immediate vicinity of any locations they might know about. Years ago there was a lot more land under active cultivation, and the people who worked in the fields knew where artifacts showed up after plowing and rains, they might be able to put you on a hot spot.