3w75 side carb? ZDZ-80 or 3w80xi will be a lot of power but good choices. Brison 4.2 would seem to be ideal, or FPE 4.2.

BME-110 is too much power and I think it's too wide.

Another good choice is the Evolution 58 with a canister muffler system. Quiet, powerful. I was hopeful we'd have seen a DA-75 by now, but nothing yet from Tucson, DA's galactic headquarters.

I don't know if there is a perfect engine.

TF