Hi Malpert there is no way to earch tthis website tfor cruises, however, this is a great place to go for answers. You want an upscale cruise line for Greece, Croatia, and Istanbul. I take that to mean you want to cruise on a luxury cruise line. Luxury cruise line pricing includes tips and acohol.
Here are the luxury cruise lines I know of with links to the website.
Just returning from a Greek Isles tour on Regent Seven Seas Navigator. Last year, did two weeks in Med on Seven Seas Voyager. Next year, have two weeks on Seven Seas Voyager to Greek Isles, Israel, Egypt, Crete, and Cyprus. I heartily recommend Regent.