I have also use Florida Yacht Charter with good results.
A few years ago I was going to use them again... until I found out I could do 10 days rather than 7 for a similar boat in the British Virgin Islands... including air fare for Less than the cost of doing the Keys charter. I would have had about a $300 fuel bill to get to and back from the keys and lost 2 days work.
Since then I chartered out of BVI several times prior to buying a boat which I now keep in the BVI. BVI has far superior sailing to either of the locations your considering but you should have some nominal training which is also available from several schools where you can charter and learn while in the BVI or USVI.
I prefer a sailboat to a motorboat, and it is my belief that boat sailing is a finer, more difficult, and sturdier art than running a motor.... Jack London