There was another one that I ran across the picture on this site.
www.ipyoa.com/photos?view=album&aid=1283
We got a number of quotes all over the country for our Cape Dory 300 Motorsailor and did like these folks: They don't need to be exact to build, just close as far as how low to start the pads.
www.customsailboattrailers.com/trailers.htm
Other option is a winter cradle that can be dragged on and off a separating drive on flatbed trailer that are used to haul heavy equipment and cheap and easy hauls.