The kit supplied pinion should already be the 22T, so if you want a bit more speed and don't want to change the stock 70T spur gear then go up to a 23T, 24T or 25T.

The Torque Tuned motors are quite decent and I tried the black Sport motors as well as a lightly tuned Lightly Tuned 28T motor with replaceable brushes and really didn't notice any difference.

Maybe best to get tires with better grip for dirt rally use.