Lonsome715,
Unless you buy new, the chances of getting the same items are slim. Each different item would require engineering changes to make work properly.
My segustion would be to purchase one old motorhome, dismantle it. Then do a proof of concept. Once you have proven your idea, then look at using new components to build the rest.
I do proof of concept things all the time. Some work out, some do not. Sometimes things just do not work out the way we think the will. Or There is no way to break even building an item.
I just had a new part made for my brake, to make 1/4" radius bends in 60thousands aluminumn. Hoping to get a contract to bend aluminum for a small Aero Space Corp. I needed to show, that I could meet the specs to get the contract.
My next project is modifying the stock airbox on KZ-1000P (Police Motorcycles), to make it easier to remove the carburators. Like others on this list, this is comming about out of necessisity. Yesterday, I had to change the Carbs on my bike. Oh boy, what a job.
I mentioned my idea for the KZ-1000P air box on the Yahoo board and have had positive results so far. Probably won't make any money doing it, but will make maintenance easier.
Laterrrrrr
Avn-Tech