RE: where do you buy from?
Balsapr.com - they rock.
Their ESC's are flawless, and work great, and are cheap too. That little 10A brushless one is PERFECT for shockflyers. No Bull ESC. Ive got over 100 flights on mine, and its still crankin'! Never had one single problem with it. Plug in the battery, it goes....PERIOD.
Their BP-21 and BP-12 brushless outrunners are fine little motors and at $26 bucks will smoke some of the more expensive motors in power vs weight.
Cheap prices, and great stuff. Ive been pleased with everything I've gotten from them. Normally I order from them through my local hobby shop. Its just easier that way.