Hi Amy; Congratulations on a MAJOR milestone in your marriage! Not many make it that far anymore!
Needless to say, I'd recommend cruising, as I think you'll enjoy the overall trip more than you will in an AI. Having said that, I'd also suggest that you stick with either Princess, or perhaps Celebrity! What I would NOT do, if I were you, is sail on one of the BIG RCI ships. IMO they are just too crowded, and unless you're really, really into rock walls, flow riders, and ice skating, the disadvantages far outweigh the advantages. They are beautiful ships, but for some reason, RCI doesn't seem to control the crowds the way Princess does. It seems to me that everyone is going the same place, at the same time. The smaller RCI ships are fine, and in fact, very very good, but I'd shun the BIG RCI ships. Celebrity ships, for the most part, are exactly what you stated you'd like,,,just a cut above the rest in food, service, and class. You already know you like Princess, so you won't go wrong with one of their cruises.
Have a GREAT cruise, and once again, congratulations!