I have two very successful 'Hawks.
Both are built very light and both do the complete "Musicano pattern".
I strongly suggest making a plywood or circuit board 3" bellcrank. Also, double-shear mounted, like a real stunter.
I know it looks dorky, but it sure gives good stability and manouverability.
The plane in the pitcher has a Cox product engine and Perfect 3/4 oz tank glued inside, in the traditional way.