Europe cruises are great and what you described would be ideal if you have the time. Not sure I'd do the Cunard Transatlantic, there are no ports. But if you wanted to go in the height of summer when there's no other alternative then look at them. I'm not recommending these guys as a travel agency, but for an excellent cruise search site, check out Vacationstogo.com. You have to register but can then search their cruise database which searches across all cruise lines. You could pick an area, such as Transatlantic or pick a port that you'd like to visit and a time frame and it will bring up all cruises in that range for you to have a look at.