Greetings Bryan and welcome.
I too am from the states, and have spent the last 50 years building camper vans.
Here are a few things I've learned over the years.
Start with a window van and save big bucks on insulation.
Keep everything portable so it can be rearranged as needs change.
Don't skimp on the necessities, bed, toilet, shower, full kitchen, etc.
By keeping everything portable, it can be used both indoors and outdoors.
Campstoves make good heaters. Double burner stoves are more stable.
If you charge your house battery while driving, you shouldn't need solar or a generator.
Use individual solar powered items, hot water, lanterns, flashlight, radio, etc.
Build to never require shore power. Minn-kota makes a great power center to put your house battery in. It has built in accessory outlets.
Ice chests are both cheap and foolproof. Use big block ice and it will last a lot longer.
Plastic bins and drawers are lightweight yet durable. One drawer can double as a sink. If you add a sturdy shelf on top, they make good work areas.
House style metal framed futons make good sofas/beds. Extend the legs to add more under bed storage.
You can get almost anything in 12v models. Inverters waste power.
Cheap deep cycle batteries are every bit as good as the more expensive ones. 6v batteries only add cost, and take up more room. They don't last longer.
TV Trays make good indoor outdoor portable tables.
Get the car cords for your electronics.
Add battery protectors to all batteries to prevent over discharge and prolong your batteries lifespans. You'll never have a battery too dead to start your vehicle.
If somebody starts talking about cargo vans and insulation, keep in mind you're talking about a lot of extra work and big money, to wind up with an inferior camper van that will get lower gas mileage, while being a lighter duty vehicle designed for in town use. If you think that's what you want, there are tons of them for sale very cheap, and already built, because they're practically impossible to sell, and the previous owners have switched to window vans. They usually sell far cheaper than an empty cargo van, and I've even seen them offered for free.
If you really want to try a cargo van, by all means buy a dirt cheap ready made one, so if you decide it's a mistake like most people do, you won't be out a lot of money. Also keep in mind that there are people getting paid to promote expensive items for your build. They're not your friends. Thrift stores, yard sales, classifieds, and deep discount stores are your friends. Building contractors throwing out scraps can be your friend.
It isn't about how much money you can spend, it's about how comfortable you can make yourself, and how maintenance free and breakdown free you can make your systems.
If you'd like I can provide you with example cost sheets. I think you'll be amazed at how cheap it can be without compromising on comfort or reliability.
Good luck, and give a shout if I can help.
