So I hit my first snag in development, see below. Current status MOSFETs ordered. I had considered re-engineering the original car's board, but I think this will yield a higher quality result. Ugh, I only need 20ma or so to drive the motors and I feel like that is achievable with a Arduino GPIO line. A hidden personal goal for this project however is to dog food many of the products I have worked on over the years, which includes the Tangier chip.

From the SparkFun Edison Hookup Guide...

If you want to use the GPIO Block to control high power LED’s or Relays, an external transistor or MOSFET will be required. It is possible to illuminate a small LED directly from the level shifter. It may not be as bright since the current output of the TXB0108 level converter is very low (~5ma).