If you want scenic forget I-10 and then I-95. I have spent years traveling on business in that corridor and other than some of the coastal marsh lands as you get to above Jacksonville there is nothing to see. We were actually in that same area last week. My brother and his wife joined us on that trip driving over from central La., they did the I-10/I-95 route on the way there and his first comment was that there had to be a better way so incredibly boring. I suggested he look at from Savannah take I-16 over to Bonaire then across to Columbus, Ga. up to i-85 to Montgomery then over to I-65 down to I-10 at Mobile. You could even at Montgomery take Hwy 80 over towards Selma and then hit I-20 over towards Jackson, Ms. There are actually a number of more scenic routes than those interstates but there is absolutely no need to go through Atlanta, or anywhere close, to get over to the Ga./SC coast.
I hope you have plenty of time to see the area, we stayed 6 days and barely scratched the surface. We enjoyed St. Simons island, the lighthouse area and Fr. Frederica, in Savannah the tour trolleys that you can get off and on are worth the money. Charleston, the Ft. Sumpter tour was again worth the money. So much history to see and much of it so well preserved. My wife and SIL are already planning another visit.
1998 American Eagle