Ford Perfect,
First, I found something called silnylon, on ebay, its silicone impregnated rip stop nylon. I think that will work fine. As far as cost, I've got $200.00 into it right now and expect to spend about $300.00 more at most. On the size issue, i'm not sure what you're referring to, but to give you an idea: The top will hinge at the top front edge, across the width of the truck. It will rise up about 2-3 feet at back. Its just enough to give me head room to change clothes, etc. My truck is a short bed so the overall camper is pretty square. 77" long by 78" wide. I could have made it 78x78 but would have had clearance issues with the tail gate.