Love your ideas. I have drifted my 40 pass Wayne S500 around snowy parking lots and attempted sandune climbing, a very bad idea, but heh that was 40 years ago. So I see where you’re coming from. Purpose built 4 wheel drive commercial vehicles are around for school busses, so start with one already engineered that way. Skoolies are cheap because they are pretty simple boxes on unsophisticated chassis, so there’s not much there and you will never Ever in a million years get insurance or plates for a modified VIN vehicle