Good luck with that... My cousin was looking to get one of those trailers about 10 years back .... and there was a 5 year waiting list then. I have no idea on the situation now.
I have heard that they sell House boats moored (sp?)at Cottonwood. The boats are older but they work and it is a place to stay in and take with you around the lake. They will even give you a lift to the house boat if you don't have a boat to get to it.