Rosalie, Sapelo Island looks like an interesting place to visit. I have only seen the light at night from the ferry dock, but I hope to get out to the island one day. Two lighthouses there.
Assateague lighthouse - you can see the light at night from the back of the McDonald's parking lot on Chincoteague. You should be safe from the killer mosquitoes this time of year. I wonder if they have painted the lighthouse yet?
Do you have a way onto Cumberland Island? That is supposed to be an extremely difficult light to see. Very cool if you can get pictures of that one.
Paul is right - St. Marks is a must see.