My dive group and I are heading to many of the same ports of call as you in 2012 - we have a couple of blogs with port specific information that includes dive operator info, dive sites, etc. Since we update these bogs almost daily, there's a ton of info, but it may take time to search for it. Make sure you also use the tabs.
We aren't going to St. Kitts this year, but dove there before - Kenneth's has their dive boat in the marina that's walking distance - you can google them and get additional information. They are a great dive operation that unlike a lot in the Caribbean, has had the same dive staffing the boats for years. I highly recommend them.
I wouldn't dive in the Dominican Republic - been there, done that - the best dive sites (and there are many) are too far. Skip St. Maarten and Antigua - our dive group won't be diving there either, despite they too are on our itinerary. I recomend you dive in St. Kitts, Dominica, Tortola (the wreck of the Rhone) and Barbados. Top three in the bunch are #1 Dominica (the Pinacles), #2 Barbados (Shark Reef is excellent) #3 Tortola (novelty factor - rent the movie "The Deep" and dive the wreck of the Rhone).
Here are our Blogs:
Dive Group Bolg - Good dive port info, articles, etc.
Dive Boat Manifest - Dive specific info, with dive site dive operator information
Non-Divers Blog - good port maps, with info on beaches, things to do in port, etc.
Good luck!
