Hello Peter,
In 2021 I?ve bought a Tohatsu 6 PS 4-stroke together with a special, large-surface pusher propeller. We were a week on the North Sea near the East Frisian Islands and had two days up to 7 Beaufort from north / north-west with very choppy seas. The engine has in every situation, even against the wind, brought the boat the necessary thrust and ran reliably.
Regarding the shaft length pay attention to the specific installation situation with your WB!
Regards
Gerold