Can't help you on a web site. The book BERLITZ Complete Guide to Cruising & Cruise Ships has tons of factual info on almost all cruise ships. Retails for $24.95. May be cheaper on some web sites or free at the library.
I know it's an old post, but I spend so much time on line to find all in one place, that I think this is a good place to share this info. It's about all big lines with really big cruise ships and their cruise ship refurbishment schedule - this is a survey on major cruise ships renovations and refits with all dry dock dates. Inside this article there's also a very interesting link - the building cost of cruise ships - and I mean all big-bigger to biggest ships and how much do they cost to build! Lots of money involved in this cruising business, huh!