I've built a few structures like that, and seen some really cool ones at the burn.
If you build an A-frame sort of structure over/incorporating your truck bed, you could have a very nice setup.
The peak on the A-frame allows heat to go up; with a small exhaust fan you can vent it out. The sloping sides are good at shedding the wind, if they go all the way to the ground.
The structure I use for kitchen/tent space is nearly exactly that. 12' tall A-frame, 22' wide, 24' long. It anchors to an enclosed trailer. Holds 2-4 tents & it's held up 2 years now @ BRC.
As far as materials, it depends on how well you design/engineer it. Lumber is solid but heavy. EMT conduit is solid & lighter. PVC is very light, but you have to work it in a tension-structure.
The camo tarp A-frame in the lower left corner, behind the GP Medium tent. There's another version in grey on the right.