Did you consider buying a camper van? They are quite common as a lifestyle traveling around Australia, in the US people use giant RVs but these are not practical at all and not a conscientious selection.
In 'Software Engineering' there is this thing called 'code reuse'. The idea being that you don't reinvent the wheel. We were all taught it (and moved on to realise there is a lot of code out there that is best not 're-used'). These Ducato vans are the popular 'platform' for camper vans in Europe, due to the low floor. Most of the conversions have worked out the hard problems and been 'debugged' with customer feedback…
It looks like the Ducato is not available in the U.S. Presumably the author could fly to Europe, purchase one, and ship it back for less expense and labor. But I think part of his venture was to have some measure of self-reliance / DIY. "How I bought a great van from Europe and now I live in it" doesn't have the same novelty and escape-from-society appeal.