Have you ever looked at the possibility of a bookmobile, or repurposing a police mobile command center or even a bloodmobile? A lot of the work is done with good insulation and a generator already installed. Those are most often 35' or so. Probably to big, huh?
I'm just thinking there must be a reason why the Goshen isn't more popular for conversion. If you got this one, it would be the third one I've heard of in the past two years. But then I have a swiss cheese memory at times. Some call it a selective memory.