The Mikron III with a little more horsepower, and more importantly torque, is probably more suitable for a Pietenpol.

The Mikron II with 62 hp really needs a clean airframe to make the most of it. Even then I have to watch weights with the Tipsy, as full fuel load or two larger people can reduce rates of climb quite dramatically.

I have done some flying in a Pietenpol with a 65 hp Continental A-65 and it too can get quite marginal with a full passenger load.

Mind you, a Piet with an inverted engine would look nice.

If you or your friend are ever in the vicinity of Bicester, we would be happy to introduce you to both types!