Vehicle dweller forums are filled with questions about all the stuff that turns a vehicle into a home. Solar, wiring, refrigeration, climate control, plumbing, sanitation, beds, storage, cookware… Less common are questions about the vehicles themselves.
I think the priorities are backwards. If you’re going to be a nomad, the vehicle is the most important thing to get totally sorted out. All the rest is optional and a lot cheaper to change than, say, a transmission. Perfect interior layouts and systems aren’t much use if your vehicle is unreliable. And it’s the nature of vehicles to become less reliable over time. So start off with it in the best condition possible. Spend your limited money there before worrying about all the rest. After all, William Least Heat-Moon and a whole lot of hippies traveled with just a mattress, duffle and cooler in their vans.