I've got that ladder holder from the Chicago guy. I ordered it for $90 and still had to supply my own unistrut. It's okay. Takes up head room, but I guess that's better than floor space. Getting it in and out can be a back breaker if you don't extend the weight away from your body carfully. I put a small hole in the top of ladder (agaist OSHA I'm sure) with a hole saw to catch the the cleat up front. It can be a little cumbersome on the lower back until you get the front hooked. To do it over again I'd still get it.
I'm a fan of the long drawers that bring the material out of the truck toward you ranther than having to climb into the truck to get it. I've been eyeing the GMC with the exterior access doors where windows would be if it were a conversion van. I'd love to swap van photos here for ideas, but I'd have to get some pictures first, could be awhile.