If you're looking for a medium (by today's standards) sized cruise ship, I'd look at Crystal or Regent. For a smaller ship for a more intimate setting, try Silversea or Seabourn. You didn't indicate which month or for how long, but those are some of the more upscale cruise lines and most should be visiting the Med at some point.
There are promotions going on that are attractive even when price is no object.