Janey,
If you don't find anything in the Keys try Fort Myers Beach--the Red Coconut. On the beach side you are on sand, 1st row is beachfront and fourth row you back up to the road (some road noise). Sites 15, 16, 17 and 18 are not beachfront but have gulf views. Very tight camping but a total beach experience. You can walk the 1.2 miles into town or take the trolley. Many places to eat and beautiful sunsets over the gulf. Just a short drive to Sanibel and Captiva islands.
Sue