If your looking for a killer motor, I would recommend taking a look at clockwork racing. Neil and John have a killer selection their able to tailor your motor to your needs. Give Neil a ring or email just to talk even if you don't buy anything he can explain the differences between quality and performance while keeping your budget in mind. Also his mills have fantastic run time there's a lot of variable to insure proper times but his mills make it almost idiot proof (10 min mile club) while on the right pipe selection.
http://www.clockworkracingengines.com/
Or
http://www.rctech.net/forum/offroad-...-products.html
His member name is maximo on rctech