We're looking to book a five night out of Miami (will be our first DCL trip, but not our first cruise). There are 2 different itineraries to choose from - Castaway Cay & Cozumel or Grand Cayman and Cozumel. We've only cruised to the Bahamas in the past. We will be traveling with our 2 sons, ages 4 & 7. Which port would you recommend? TIA!!