TCWed10, the weather was really perfect. Everyone hung out on the beach, swam and snorkeled all day and then evening was beautiful, no sweater or wraps required.
Winnie, I think the only all-inclusive you're missing on your list is Club Med. I didn't visit any of these but I think they are the only 3 ai on the island.
Breakfast was included in our Gansevoort stay and they hooked up a 10% off deal for our guests at the restaurant. You can negotiate stuff like that with your hotel (and, again, the Gansevoort were really, really willing to work with us), especially depending on the time of year you have your wedding.