So I ended up ditching the gearbox idea and went very simple as a few have already done. I used an APS 80100 80kv motor (unmodified, no epoxy, etc.) with a castle creation phoenix edge 160 esc. Prop is an aluminum 7 1/4 x5 available on banggoods or ebay. Board is a 7’3" paddle board I had already. Foil is a chinese takuma with a front wing I made.
I want to thank Matt and the others on here who have shared their files and did most of the design work.
Did a trial run this morning and could not be happier with the power available. I dont think I ever went above half throttle. Seemed to take 51 amps to get on foil and 38-42 amps