The largest all-amateur competition in your area would be the Southeastern Regional Championship on October 14 & 15, 2005.
http://atlantasrc.org/
The largest competition overall in Atlanta is called "Hotlanta Dance Challenge," and is October 12-15.
http://www.hotlantadance.com/2005/2005default.htm
That's kind of crazy that they overlap like that. I wonder if it's always been this way?
There might be others, but I don't live in Georgia so I really don't know for sure.