most cruise lines wont offer a return transatlantic sailing as one itinerary - you will have to look for a date that it goes form Ny and then for another date that it would leave to return to NY. There are quite a few cruiselines that offer transatlantic crossings from NY to UK but not many from NY to Amsterdam. Holland America cruiseline would probably be your best bet (the clue is in the name)
have a look at http://www.cruise.co.uk/cruise-lines/holland-america-cruises/ for holland america itinerarys and ideas.