I don't know of any places to off road in the areas you are talking about. Thought I'd at least let you know I read your message !!! It's "way quiet" on the Georgia Chapter site, to say the least ! Just a bump for you buddy, you might check some of the Jeep forums.
We go wheelin' off Union Grove Road in Lithonia just down the interstate of Conyers. Its a powerline/undeveloped neighborhood. We never have issues with police. There's mud, rocks and trails. Our truck club organizes trips about every month, let me know if you head out there.