I recently found an excellent online resource for anyone with a disability trying to plan a cruise. It's on Vacations To Go's website, they have an entire section called Special Needs. Not only does it give you more information than I've ever seen in one place, it also allows you to search for ships and dates based on what your needs for the ship are. Here is the website.
http://www.vacationstogo.com/special_needs_cruises.cfm
I called and spoke to Katrina and she was very knowlegeable. Apparently they have a whole department dedicated to working with travelers with disabilities! Hurray!