How about looking into booking a Thomson cruise. This is a British cruise line with about 4 ships & a casual atmosphere. You'll find that gratuities are included and I believe that you still have singing waiters when you eat in the main dining room. I believe the Destiny & Celebration are nice ships to cruise on (but suggest you research carefully if you are interested in booking the Thompson Dream...some former passengers seem to think having an enjoyable cruise may depend on where your stateroom is situated.)
The other thing you might like about cruising with Thomson compared with some European cruiselines like Costa & MSC is that English is the main language onboard.