Hey! Welcome to FlyerTalk.
Any ideas where you may want to go to the Caribbean? It's actually my favorite travel destination and I go there with miles/hotel points all the time. Just went to Grand Cayman in November. You can actually cover your hotels with the cards too. If you give some ideas of islands you may be interested in, we can also recommend some cards for that.
I see that HCA recommended the Starwood SPG. This is actually quite a good deal as they have three hotels in the Caribbean - Westin St. John, Westin Dawn Beach in St. Martin and Westin Seven Mile Beach, Grand Cayman and you should be able to spend 5 nights at any of them for 48,000 points.