You are worried about fighting tailheaviness? It sounds like you are on target to think that a .91 won't haul the plane around also. Maybe start with a heavier, more powerful engine in the nose like a 120-150 size 4 stroke.

I don't know squat about the dynamics of airfoils, but that sure LOOKS like a curiousity.

I just finished a clipped wing Aeroworks profile Extra. It weighs 9 lbs 8 oz including 3 oz of ballast in the nose . Power is from a YS 120 . For all around fun fly performace the engine is purrrfect. Takeoff vertically, hover all day, great throttle, etc...

-Cheech