On Grand Cayman, nobody beats Nick Buckley who now runs 2 - 6 packs and offers very personal service.
Hiscompany is called Red Baron. I don't have the web site on hand, but I'm sure a quick google search will find it.
I get down to Florida on a regular basis and I think that the West Palm area is a great deal that offers very good drift diving. The fish life and quantity is hard to match.
For an easy gathering, I vote for West Palm (that way I can dive and work on the same trip)