Chevy Express 1500 with bulkhead divider and fiber body liner...the ultimate full time kj/dj vehicle. Affordable to buy, operate and most square footage for the buck in cargo area. Great gas mileage and low operating cost and high reliability. (Have 80,000 miles on the original tires!!).
As a backup I have a Dodge Ram 1500 cargo, and as a backup for that a Toyota p/u with a 5x8 enclosed aluminum trailer.
When I started in the biz, I started with the trailer, but moved into a van shortly thereafter. It sucks when you break down and AAA wont pull the trailer to the garage. After sitting with the trailer waiting for a friend with a trailer hitch to come and get me, the van became a no brainer.