Another suggestion for South Florida is Key West. I lived on the city operated Mooring field for quite some time 3 years ago. The moorings are cheap ($120/mo. in 2003), the pump out boat comes once a week, they have a beautiful dingy dock, water for your tanks, garbage removal, shower facilities if you need them ...even parking for your car..yes...even parking. Get their before winter sets in as they always fill up when the wind pipes up.
Or you can cheaply hire a local to drop in a mooring and fight out the parking and dingy space at the local docks. Waste removal will be your issue in that case. It's a beautiful, small town place with wonderful, laid back people who really know their boats. There really is no place quite like it.
As for the boat...it really doesn't matter what you have... the boat has very little to do with the lifestyle you choose. More important to get a boat that will not break the budget and that you feel a connection to, because all boats are comprimises of one sort or another. Good Luck!