Gib,
You're getting some great suggestions, but I will second what
A.G. has expressed re: Atlanta driving times... they are highly unpredictable and if you live here you quickly realize that it usually takes longer to get to places than logic would dictate. Both The Frog and Cobblestone (though it is Ken Dye circa mid 1990's, not '80s) are good suggestions, but I wouldn't bank on 40 minutes from the World Congress Center for either one, especially considering the magnitude of highway DOT work occurring in the ATL for the remainder of the year. In fact, any effort to drive north from downtown might very well encounter traffic.
Additionally, if your friends are concerned about course conditioning, then Cobblestone would be hit and miss as it is traditionally wet and conditions are rarely predictable. The Frog, though, is often in very good condition.
Summergrove is another good suggestion that, once again, might stretch the drive, I don't know for sure as I have never made that drive from downtown in typical traffic. I know many people, though, that consider Summergrove one of the best courses in the metro area and definitely one of the best values around.
Hope this helps some.
Keith.