Pull Out "Deck" Design

I cam across this design on an offroad forum and it showed vehicles with roof top tents. I especially like the Flip pac design. take a sec and google it so you know what I have in mind. Id really like this however the camper shell would not fit in a chopped 4runner. (google image that too) So my idea is this.. Id like to construct a mini flip style tent that flips forward which would be the full length of the hood and roof (roughly to the end of the rear doors if you didnt see the chopped 4runner) ok so to maximize the size Id also like to slide out another section that runs the length of the "bed" section of the 4runner. In order to do this I am looking for a substitute to plywood as its so heavy, but I need something very strong as Im sleeping up there! Any advice on alternative materials and construction of the "slide out" as well as the hing for the flip would be greatly appreciated! Thanks!