Dave Patrick ULtimate 1.20 Bipe engine????
An engine that is often over-looked for the kind of application described is the Thunder Tiger 1.20 (actually 1.27). I equate its performance with many 1.40 engines. For example: one of my TT 1.20's is currently running in a H9 78", 12 1/2 pound Edge with a APC 17 x 6 (erroneously not listed but available) turning 9,000-9,200 rpm using FAI fuel. Tho not unlimited vertical, it will pull up out of a torque roll. The standard muffler with the lateral mounting adapter will not fit inside the Ultimate's engine cowl. A Bisson would be more appropriate.
Hope this helps with your decision.
regards,
DGO