Before going hunting, one should have a well developed idea of what they would like to have.
The hightop fiberglass roofed long wheel base extended Van is one (or has been) of the most sought after.
An extended Van would have perhaps another 24 inches of body behind the rear wheel. (like an extension behind the rear wheel)
But newer Vans and styles are becoming more available now days.
Many of these Vans are in the form of 1/2 ton. But they are also made in 3/4 ton and 1 ton, which are more rugged.
Aluminum body step Vans have loads of room and resist rusting. (making replacing the engine/transmission if necessary a more attractive
proposition. A well cared for step Van could last for some time.) These are often used for Bread trucks, or for delivering potato chips & snacks. Automatic transmissions are more common in these now days and many of them get rather light usage. But the can easily be built out and worked on. Plus they are built like Trucks.
If I were looking for a Van with a High Top, I'd look for one without windows except in the front and in the back doors. If it doesn't have tilt out rear windows, you can find those on a wrecking yard and install them yourself. I did mine. Just make sure to get the window gaskets with the windows as
you will cut/destroy the old gaskets when removing the fixed windows in the rear doors. Being able to open the rear windows will allow for a nice breeze when driving or some air when camping. Most commercial delivery Vans don't have side windows, they are all sheet metal which makes for easier insulating and build out.
You can visit the top link in the two below this post. "Van Conversion".
As for will any Van work, it will depend on what you are wanting to do. If you want a starter to use on week ends you will still be wanting something
that's in fair shape with some miles left on it. I would suggest going with a gasoline engine if you are in a colder climate. Yes, some makes & models
have a better track record and Google searching may be the easiest way to learn about that. There are auto-brokers in various parts of the USA
and they have "finders" software to locate who has what. They will charge a fee to locate something for you, and ask how far you are willing to travel to buy it. Also what your budget is for the vehicle you specify. In some cases it may be cheaper to do that than drive all over the country for a year hunting with that much gas and time spent that could have been used with a broker so you would have had the time to build out your Van.
In an 18 ft long step Van you would likely have a 5 X 10 area you can stand up in. That could be built out nicely for one person on the road or to boondock in for a few days. You may not need dual rear wheels either.
Other things, will you have room where you live to park it when not using it ? Will you have valuable items in it that should be stored in a secure place when the rig isn't in use. (aka generator, kitchen equipment, tool kit, sound system, laptop, camera, and anything else a thief could steal)
This is just some brief things to consider. Good luck !
