Been a hammock guy for 10 years. Works very well for me. I installed a ring to a pillar just behind the driver's seat and an eye-bolt right by the rear doors (diagonal across the van). 10.5' cargo bed. You'll need some rope on each end so things hang properly.
Lots of resources online for hammock camping. I made an under-quilt that hangs below the hammock so my butt doesn't get cold. Didn't think I'd like the hammock at first, as I'm a side-sleeper. But a proper nylon camping hammock works just fine -- and I'm 225#, so no light-weight.
The biggest negative is that some overnight loads won't let you set up the hammock. I have a simple foam mattress that's kept strapped to the ceiling 90% of the time, but can be put on the floor in the 2.5' gap between the bulkhead and cargo when I'm hauling two full-size pallets.
Look up Hammock Camping for lots of tips and tricks.