Doesn't sound too bad for the 80/20 costs.
Here's an atv ramp approach like mine. I cheat since I have L-track above the window line and also in the ceiling at the front edge. So verticals are two simple perforated steel strips.
http://www.tractorsupply.com/vehicle-ramps/reese-reg-farm-ranch-single-tri-fold-aluminum-ramp-45-in-w-x-69-in-l-1035113
This trifold gives you 3 15x69 "shelves" for $99 + shipping. All of these "laddered" ramps can be shortened to the nearest ladder for neatness or just shortened and capped.
My bifold ramps have useful 1/2" lips and weigh 12.5 lbs. Maybe 13.5 lbs with vertical strips and L-track connectors. 15"x72"x1.25" each ramp. Rated for 650lbs each section.
Admittedly simple. Lots of weight/strength optimization and lots of robot TIG welding. Since my laddered 1.25" box beams are rated at 650 lbs it suggests that the smallest, lightest 80/20 would be plenty strong for the less than 100 lb loads you might store.
Or even skip the 80/20 and bend some 1.5" metal strips by 90 degrees at the front lower lip and just hang a 1/4" ply floor. Add a front Al angle if you want the metal look. Could be 3 lbs of metal and be quite adequate.
I did not feel the need to add floors, sides or doors. I find the minimalist open look makes the van brighter, airier and feel less claustrophobic. Certainly not for everyone.
I hang paddles and the like to the underside one of my shelves. I even store a section of my bed ramp by its slip pin, folded neatly back to the underside.
My awning crank and a real broom store from the ends. Some of my kit duffels are more than 3' long and sometimes go up there. Mostly clothing and bed pillows except for the three perforated plastic bins over the kitchen. It is a lot easier to take a breakfast bin out to the picnic table or to the counter space than to pull individual items from drawers or shelves. Particularly before I've had my first cup of coffee. Moral here is minimal verticals gives more storage choice. Your option if you need to hide what's up there with doors or curtains.
I mocked up the inside of my van for hours and hours before I built it.
My overhead shelves are 12' long on the driver side and 6' long on the passenger side. The passenger side does not run all the way to the rear door to not interfere with using that door. No qualms about running the driver's side shelf all the way back since opening both back doors gives such wide access.
My shelves are 15.25 wide at the bottom edge. (1/4" added to attach the 15" ramp to L-track). The inside height is 10.25". Outside height at the front edge is 11.5". Since I'm tall this width should work for nearly everybody. The height is a different matter. While it is important that anyone sitting under the shelf have enough clearance in my case it was useful to be able store a bicycle under there above the wheelwell shelves. This worked well--I do not store bikes there often but sufficient human clearance is psychologically good---better to not go with minimums.
I am probably a good stand in for dimensions needed up to the tallest 4% of Americans. (My wife is 14" shorter and many of our work heights apply to much of the population.)
Hope these data points are useful.
Dan
