Did you end up getting the brushless variant yourself? or still working one your cousins one if I remember correctly?
I finished that build and gifted it for Christmas just a few days ago! Went with a Truggy build, 2700kv 3650 motor, 60A ESC, 13/48 gearing, and a 7.2V nimh pack to make their battery management foolproof & fireproof... and now that I have enough spare parts, I'm tempted to make an onroad to go with it.