Brunswick Landing and Golden Isle are good places in Brunswick/St Simons. Jeckyl Island marina is an interesting stop. There are places in St Mary's that are cheap but rather 'rustic'. Those are most of your choices for S Ga.
I noticed your comment of doing the keys and Bahamas. Leaving Ga in Jan, I'd skip the Keys. Takes some time to get there, takes some time to visit but the worst part is going upwind to get from keys to Bahamas. Lots of boats sit quite a while waiting for something less than 15 on the nose.
If you are well under 5' draft you can go inside with better conditions.
But the Bahamas are soooo much better than the keys, so why bother?