Why build your own when this is for sale?
 

Not too fancy but all the comforts.... ;)

it would make a fine cottage for back in your woods, but 'ya ain't taking that down the road anywhere. The first LEO you passed would order it off the road. Good theory though. Used van trailers are a dime a dozen.

I noticed that the converted semi trailer is no longer listed on Craigslist. Did you end up buying it?