I DON'T know if the small N20 gear motors would be sufficient for this build or not.
If the servo idea doesn't pan out, perhaps I'll attempt it with a couple of them. I don't even have a clue what RPM would be well suited to this build. HOPEFULLY the servo idea will pan out. I've seen vids of the stuff that SmallHaul has converted. His looks good, & are very functional too.
I'm sure with a lil tinkering, I can figure out how to get them servos to work for my drive motors too.