Nice. The "Mirage" is a beautiful unit, albeit heavy, I think. The second one comes closest, but it's still a "slide-in", and appears to use up space along the sides of the bed, which I want access to.
I want a "sits on top" unit that doesn't slide into and consume the side space below the top of the truck bed. I'll likely have to build this myself from scratch using aluminum or light steel angle for the perimeter over as a framework. Then I can overlay it with aluminum sheet. I don't think these things need to be elaborate, heavy, or expensive. It's just a TOP, after all, and no weight will be on it, other than it's own. A small 1-2" lip along the top/inside of the truck bed would hold it in, and I think weight would be far less than 200lbs. My current fiberglass low-top unit uses four clamps to hold it on, and I can get in on my knees and lift it right off by myself.
The commercial-made units I see max out the weight limitations of every truck bed I've seen so far, and I just can't see the sense in that. 400-600lbs? Seriously? The only reason I'd use a hard top at all is because it's easier to keep warm or cool, and harder for a bear to eat me in a hardshell than in a tent. I hate surprises almost as much as bear, and I tend to react about the same. Otherwise I'd make a tent-top camper, or just use a tent.
I like the outline of Bob's original camper top, but I don't want to use wood, either, due to weight, although that would seem quite resilient for a home-built. I'm no carpenter. I'm a former sheet-metal worker, so I'll stick to what I've had experience with.
Thanks for the replies, gang!