It is not difficult to "stealth camp" in the Atlanta area. Park and ride lots, non gated apartment complexes, Publix parking lots and street parking are all viable options. I spent quite a bit of time this past winter there. In particular, I've used the Indian Creek and Panola Park and Ride lots, East Lake Publix, a few Planet Fitness locations in or just outside the eastern perimeter, and a couple of apartment complexes (I don't remember their exact locations but they were in Dekalb county). My spots were chosen based on proximity to the business I needed to conduct. I think you'll be fine in whatever section of town you want to be in.