atlanta is great. unless you are loaded, i wouldn't even look at a house in atlanta itself. even if you found one for a good price, you'll pay a liver and an ear for taxes.
if you want to be in the ATL area, i'd definately go metro-atlanta. since a racetrack is a must, go with what baha said, pretty much Gwinett county. Anywhere in Gwinett that is near the interstate because commerce, GA has a racetrack and you would be taking I-85 northbound to get there. metro-atl is really based on the interstates, I-75, I-85, I-20, and of course I-285, but of course there are backroads.