i've been looking for this one too for future fun.
if you look at Sweetwater's website, they list some of the ingredients:
Grains: 2 Row, Munich, 40L, 70/80, Carapils, Chocolate, Black
Hops: Columbus, Willamette
might try playing with those in whatever recipe you go with. also saw a reference to Marthasville Brewing's "Sweet Georgia Brown" as being similar. you can google the full recipe for that, though it's definitely different from Sweetwater's at a glance.
good luck, one of my favorites.