I drive a fullsize Chevy - had a cap, but no side access. The only close compromise I could see would be an ARE 'DRU style' cap (aluminum with the side-mounted tool boxes where the windows normally go), but there's still a lot of wasted space.
My buddy (ex-foreman) drives a 2500 Chevy 4WD w/ a Reading utility body with drawers and bins inside most of the cabinets. He made some 'custom' partitions to allow bins and long tools to co-exist. He's a Lt. on our VFD, and also mounts a quick-mount plow on the front for a few 'friends and family' accounts. It's nice in the winter when we were the first ones there to be able to plow our way in - instead of following the ruts left by other contractors. 4wd helps when responding to fire calls as well.
He hated crawling around in our bosses van (e-250) - seems like everything wound up on the floor, or behind the stuff that was on the floor. He's got all his parts and such organized pretty well.
Before our shop folded, he also had (2) of the 96" long 'topside' type boxes on top of the side cabinets for extra storage. A lot of room, and everything had a place. Not as much room as Tom (Active 1's) step van, but pretty decent. Now that he works for a shop with vans (and he's not the mobile supply depot), he dismounted the topside boxes.
I've been looking at a service/utility body that's 128" long, with a low-rise sliding roof. This will enable me to haul sticks + supplies inside the body, out of the elements and secure from crackheads (a problem with my foreman's rig). It'll be a little bit longer than my current LB chevy, but not much.
