Wendy, be sure to try out any boat you're thinking about--this includes getting it on and off the roof racks and getting it onto the water, paddling it in wind, etc. You did not give any info on your physical dimensions, weight , etc. Sea Kayaker magazine has lately been reviewing more sea kayaks in the 14-15 foot range; many of these are of lighter weight and easier to move about, on the water or off it. Florida paddling is not as demanding of the boat as are many other areas--less likely to be paddling in huge seas, rock gardens, wicked tide races (there are exceptions, of course), so it might be more important to focus on getting a boat that really encourages you to go out and paddle by making you very comfortable getting it onto the water and paddling it around.
Since Magooch put in his usual plug for NC Kayaks, I'll add mine for my Epic 16X, which my Florida paddling friends tell me is popular down there. The boat is only 16 feet long, stable, LIGHTWEIGHT, seaworthy, fast, relatively stable, holds a lot, very comfortable and, sadly, expensive.