There are 3 AI hotels in a row, in ascending scale of star rating:
Blau Costa Verde
Playa Costa Verde (the one I've stayed at twice, and can recommend)
Playa Pesquero.
Check out the Thomas Cook website. Their flights have good leg room for such a long journey.
Caya Coco is a nature reserve off the coast of mainland Cuba, there are a few hotels there, we stayed at the Melia, which was fantastic, especially if you like lobster omelettes for breakfast, food and drink, including champagne available 24 hours a day, I don't think they allow children under a certain age though. Sorry I still can't do links.