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. The swivel seats come already done properly with no hammer needed. The various tanks for various fluids are worked out. Spares can be bought, plus you get something better than really heavy plywood carpentry - actual cabinet-making.
We all have our own dreams, however, from my experience of living with a camper-van mad family, second hand is good. I would not go for brand new van that depreciates and custom prototype carpentry when people vastly more experienced than me have done it all before hundreds of times over.
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.
#vanlife was on the fringe about 5 years ago, but it's starting to gain wider acceptance in the US. I would hope that within five years Volkswagen will finally bring the California T6 to the States.
At least here in the Pacific Northwest, old VW Westfalias seem to be the hot item right now (I know of at least two Westy-specific repair shops in just Seattle). But I have no idea what it would take for VW to import them. Getting rid of the "chicken tax" would be a start, as that's going to add 25% to the price right off the bat.
Sprinters, Ducatos, Transits, and NVs (not to mention old school Expresses/Savannas) are already available here, so I'm not sure what a VW California T6 would offer that the others wouldn't.
- OEM. You'd need to go aftermarker for a pop-top. And as as awesome as it is to DIY, not everyone has the time/skills for a conversion.
- Volkswagen cult appeal. You can't deny there's a demand for older T2/T3s and Westies. They released the Beetle for nostalgia, they can do the same for the T6.
