does it really matter which way it turns surely you just mount the motor the other way around then it spins in the other direction doesn't it? hope it works out for you I assume a battery will be part of your fuel cell so to speak any thoughts on fitting a charging system to it also? could work out to be free power
if a system could be worked out properly
If you go with a GR or gear reduction starter, then the output shaft from a Honda starter motor is typically clockwise and from the others like Nissan and Toyota, counter-clockwise. The rotation of Honda car engines is typically "backwards" from everyone else. Not sure if this still true for the latest models.