It really depends on how you want to chunk out your driving days. We tend to like KOAs for overnights en route...kind of the Applebee's of the campground world, IMHO...not the most spectacular, but you know what you're getting will be satisfactory
I just did a quick google map assessment on the options we'd look at:
Fayetteville/Wade KOA: 7 hours Sat, 8 hours Sun morning
Point South KOA: 10 hours Sat, 5 hours Sun morning
Savannah South KOA: 11 hours Sat, 4 hours Sun morning
Jacksonville North KOA: 12 hours Sat, 3 hours Sun morning