Im super rusty with my PS skills so I decided to mess around and see if I could make something that wasn't a total Frankenstein haha.
I found this easiest to do (of course) with a side view.
This is not a quad cab.
Behind the front seats (no idea how you would fit them in lol) would be a back similar to a pick up cab, maybe with a sliding window?
The rest of it would be open all the way, kinda like a cave. Some sort of weird engine cover would have to come in somewhere. The floor would be replaced with a truck bed floor stitched in.
You could probably rework the back (heck if you could do what's in the picture you could make anything out of metal

) to incorporate the rear portion of a pick up box so you could have a nice tailgate.
I also think a nice builders rack that went from rear to top of the cab like specialK has on his truck.
Another thing there was a drawing on the board (lost it again) of a lowered short box with work boxes sort of melded in to the bed sides. That would be cool and useful.
There ya go ... Dare to be different work truck.
I blame this on a lot of people haha! But mostly Longhair from when the photoshop board was active. He made a snubnose Burb van ... It was cool.