Cruises: Looking for some Advice

Sounds like you're limiting your options due to port of departure and duration. Betting there's only a couple of options available to you. Just spend the most you can afford and enjoy your time. I've cruised Carnival but I'm convinced they're all comparable. I wouldn't sweat upgrading your cabin either. We slept in ours and that's it. If you want luxurious sleeping quarters then spend a bunch of money on a hotel.