[Al Skierkiewicz]

I think you will be unhappy with the performance of the bevel gears transmitting power. The design linked above with the motor in the crab module has worked for us when we use crab. It is easier to get wires into a turning assembly.
We always find ourselves reminding teams that they shouldn't dedicate themselves to a particular drive system this far in advance of the kickoff. We use crab drive if and only if the game needs it. There are tradeoffs for weight and programming that could be used for other devices.