Location, location, location!!!
Don''t know about slip availability but there is a little town just north of Clearwater and just off US19 that I saw a few years back. It seemed like the perfect place, lots of slips, 5-star restaurant and if your budget is more limited there are all kinds of restaurants and little pubs (my kind of place) along the main drag into the marina. It also has access to the gulf via the intercoastal (barrier islands exist).