trailfinder build with a super rooster, what motor?

[obrut]

Well after a few years away from rc cars, I come back to find all this great scale stuff. I still have my bruisers and mountaineers from when I was building crawlers. I just ordered a new trail finder kit from RC4WD and planned on using a super rooster I have laying around. Just woundering what motor and pinoin I should use for this trailfinder with the R2 trans that will make a great crawler.

Thanks,
Tim