Look for a medium duty ambulance on the Topkick/Kodiak chasis. It might be easier to find. And if you get it from a smaller rural service it'll probably be lower mileage and in good shape.
So I found this while looking for a new vehicle.
https://galveston.craigslist.org/cto/d/2007-chevy-colorado-service/6272443996.html
It looks interesting and that box can be stripped out. tempted on picking one up for light expo trips and xc trips. Anyone seen one set up as anything other than a...