Here's one in Riverside CA.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=15272&item=7140905237&rd=1
And there are several other boat/trailer combos. The boats are crap, but the trailers might make a good tear frame.
It might be worth picking up someone else's junk for a steal, dump the boat in a landfill, modify the trailer, and off you go!