Another idea is Jack’s BBQ in Kingsland GA, exit # 1.  It’s about a half-mile west of the exit, across from the truck stop.
 
Closer up to Savannah, there’s Smokin Pig BBQ in Richmond Hill (exit # 102), about a third-mile east of the exit.
 
I thought Jack’s was pretty good and Smokin’ Pig nearly excellent, but I’ve been wanting to try B&J for years and would definitely take that if it is an option.