There are two active leagues in Atlanta, both are played at private locations. Make sure you check out the IFPL site for a list of all leagues and tournaments in the area.
APL - Third Saturday of the month, 24 players. Group match play.
Atlanta Head 2 Head - Played Thursday nights, 12+ players. Head to head match play.
I am the AH2H Director, so shoot me a pm if you are interested in playing. Our next session starts in August.