I built the topper for my truck inspired by the maker here on cheaprvliving, but changed the roof line as I wanted to be able to stand up in it. My version also gave a slant to the ridge to allow for drainage as well as height...And, its not perfect, but it works. Instead of laying 2x4's on their side, I used 2x6's on edge, trimming the ends to 2 inches above the walls and then on the underside I trimmed to 2 inches in the center. I can stand up in it and was able to put 2 inches of insulation in as well. Also, I have a 5th wheel hitch bolted to the floor, so with laying 2x lumber on its side and puting 1/2 plywood over hardboard insulation, I am still able to stand. I am 5' 8 1/2 inches with my boots on. I like the design of the one on this site because it gives ridgidity and stength to the cabover section by using the cantilever design. I sleep in my cabover at the moment, but if I can manage it, I'd like to sleep below and use the cabover as storage.<br /><br />I will try to download the pics of the progress of the truck, but tonight I'm ending a 24 hr migraine and I'm brain dead with a headache, so thinking is out of the question. Good luck on your build...Rae