I'm Always using tamiya pinions/spurs.
The only thing you need for being able to use the smaller spurs and larger pinions is the high speed gear set.
You are able to use the kit supplied motormount, but you need to check out the position of the motor on the motormount to have the correct gear mesh.
I'm Always using the 04 pinion/spurs, don't know what's the same when using the 48 or 64 pitch pinions/spurs.
Hope this helps