scratch Bonaire off your list... no pelagics and long travel time to get there and back would suck for such a short trip.
Cozumel? Well, I have seen some nurse sharks there on occasion but not a regular guaranteed thing.
Bahamas - yes you will see sharks, on regular dives and shark feeding dives. We've done two trips on the Nekton but those are 7 day liveaboard trips - lots of sharks. Since you are only doing 4 day trip, I would think about going to Stuart Cove's. Unfortunately, I think they have bigger boats. I think there are only 2 dive ops to choose from and the other is the same size op. Other's may have more info on that.
Florida - yes, southeast coast from Ft. Lauderdale north to Jupiter has diving with occasional sightings of sharks. Once again, not guaranteed.
All that said - from your list of wants and that it is a short trip -go with the Bahamas.