Fayetteville / Peachtree City is a good choice for hotel. I agree with @Cami Kelly in that SFoG general area is not comfortable or welcoming, nor would I recommend the area around the ATL airport (Hapeville, etc.).
You will LOVE ArieForce One, and good timing, as it's shutting down Aug 2. Hopefully their go cart track is open, as it has some comical airtime on its hils.
If you have a Six Flags prestige pass that allows all parks, you might want to sneak in Six Flags White Water in Marietta, which has comically low attendance during the week even during the summer. While SFoG has Hurricane Harbor built into the park in the most awkward way possible, it seems to be always SLAMMED during the summer.