First of all, congrats on your big day! If you're considering doing a cruise, I think it's a great way to go. Usually everything on a cruise is inclusive EXCEPT for your booze, shore excursions, and gratuities. The things I like best about cruising is you get to see a different place each day, and of course....all the food!
We cruise on Royal Caribbean, and the ships are immaculate, the service is outstanding and there's alot of things to do onboard. They actually go right out of Bayonne at the Cape Liberty Cruise Port. You can save some $$$ by booking an inside or an ocean view cabin. They're the same size as the balcony cabins, just with no balcony. We usually don't spend much time in the cabin, so even though having a balcony is nice, it's really not all that much better. Just try to get on a mid-level deck because there's usually less 'movement'. On that note, if you're concerned about getting sea sick, you can wear a dramamine patch behind your ear. It's about the size of a dime or smaller, and they must work because I saw quite a few people wearing them.
We stopped at St Lucia on our last cruise and spent the day at Sandals, Halcyon. It was very nice, and I got smashed at the swim up bar, but I honestly don't think I would've been happy spending an entire week there, especially for the $$$ it costs. I'm pretty sure Breezes and Sandals are the same company, but Breezes is a family resort which is probably why it's less expensive.