Have you seen this fellows work:
Practical VanHe has some really good ideas without all the Glitz associated with the Roadtreks, Pleasureways etc. Plus he kept his ground clearance by not running pipes, valves etc under the van....
You have a good project going, I think there will be many more like you utilizing the Dodge Promaster and Ford Transit chassis, the hard job is already done with these new vans, you dont have to raise the roof.
They are built almost square inside, easy to frame up with cupboards, counters etc, just build them and set them in, ready drilled holes, many options for tiedowns, 12 volt power, dual alternators etc can be ordered from the factory, different window configs etc..
Any one a bit handy should be able to convert one for on the road travelling. Keep it all white, paint a company sign on the side and you will fit right in at truck stops, industrial parks etc...
There will soon be thousands of them runnning all over the place. Ford doesnt make the Econoline anymore....
He shows pictures of insulating with spray of some kind, he is close to you.