Boy, it sure is great how supportive people can be when someone has a different idea. Personally, I don't see why the design goal here can't be met. It seems you're pretty intent on making this happen, and have a capable pilot to participate. The requirements in the first post were to accelerate on the ground, launch off a ramp, and glide down a hill to a safe landing. I saw no mention of climbing to altitude under power and maintaining powered flight, at least in the initial posts--correct me if I'm wrong. The sketch in post #1 is very short coupled and would be twitchy, but other than that I see nothing to preclude success here. If you can keep the total weight at about 7.5 lbs, it would have a wing loading around 28oz/sf, whereas the avistar wing loading is about 20oz/sf, so it will need to glide FAST and will have a high sink rate, but it should be do-able.