Here is a Curveball if the size of the Class C is not negotiable;
Have you looked at the ex rental Class C units on the Ford Chassis from Cruise America.
https://www.cruiseamerica.com/rv-ren...les/compact-rv
Or even better yet, go & visit them, rent a unit for a week.
And then rent a Class B Roadtrek/Pleasureway in a 140 or 170 or US Ford or Chevy chassis.
If the Class C still appeals, rather than adding in the cheap build of such rentals with their design focused around ease of access to fleet maintenance & repair, simple to use newbie controls & barely adequate amenities, go the other way.
Find a box truck manufacturer that makes such starter frames & build yourself, the ultimate Class C.
With that box type as your template, put the Dream Machine upstairs into gear & build yourself the ultimate Class C with high end materials, sophisticated controls & features & enough investment that is prudent, tricking out the ride experience itself, with Professionals like Weldtec, Supersprings, etc.
You seem to me, the guy who could make it work ...