Chain pitch for drivetrain

A couple years ago, I was able to pick up 12 of the legendary EV warrior motors from a surplus deal (think speed 900s, but a bit bulkier). I'll be using 2 of them for drive in a featherweight wedge/plow, using roller chain for the geardown. What size chain pitch would be best to use? 0.35 is sturdier (and heavier), but if I go with 0.25 pitch, I can get away with getting the reduction I want in a single stage, saving weight and space inside the frame. Which should I go with?

25 pitch is way more flexible from side to side, so it derails more easily. It has more than enough strength, so if you keep the sprockets close together and keep the chain tensioned, its the better choice. Adding UMHW chain guides might be a good idea as well