Think you should be heading straight to Seabourn - they are absolutley wonderful!!
You are looking in the main at the high end of the cruise market although other cruise lines will accommodate you. Top end is Silversea then Crystal, Seabourn and possibly Azamara and Oceania ( that's the company not the P&O ship, I seldom recommend P&O) My first choice would always be Silversea but it is nearly as expensive as the price they want us to pay for the bookings on the Queen Vic!!!!.....Neil Dow.
I recommend a celebrity or royal caribbean cruise. the navigator of the seas ( RCI boat) is beutiful and you'll be treated like royalty. I have yet to try Celebrity but they are owned by RCI and they are 5 star so you wont go wron.
We have done a mediterraean cruise in August 2007 on the Freedom Carnival. This was 8th cruise and have been on many lines it was fab and treated us well the rooms were fab and food brilliant especially the Sunking Lounge wonderful. Would recommend it.
You could try Princess Cruises.
We booked on the Sea Princess, room with balcony through Bath Travel and asked for a table for 2 second sitting, which luckily we got - as there are not many tables for 2! Enjoyed the cruise - Mediterranean - staff excellent - cabin good, though luxury? Depends on your definition. Had previously been on the QE2 - Caronia - Table for 2 and to us that was luxury!
I agree Royal Caribbean and Celebrity are great especially with a suite and butler service but trying to get a table for two on them is not impossible but it is not easy either.
Splendour of the Seas, we had a balcony stateroom on the back of the ship deck 6 and it was lovely, the dining room is spectacular and has tables for two if you book them.
I recommend RCI or Celebrity Cruises, I was on the Constellation for the first time in May to the Baltics and it was brilliant ,first class service also RCI is excellent too ,this is the sister company of Celebrity,I would recommend Voyager,Serenade of seas or any ship of these 2 companys,Happy Cruising it is brilliant Regards Iren.