There was a Sunnfjord custom built for a couple where the wife had MS; I think it was about 48' or so. Anyway, it was up for sale on Yachtworld a while back, and while I don't remember the price the exterior looked a bit worse for wear so if it is still available (it's no longer on Yachtworld but there could be any number of reasons for that) it might be reasonably priced.
This boat was covered in a PMM article when it was new; everything was on one level except the pilothouse which had wheelchair capable elevator access.*
The Sunnfjord site has some info on the yacht:
http://www.sunnfjordboats.com/pg/projects.html
*
Good luck with your search.