If you decide to go with a "stand-alone" system, the haltech seems like the best way to go right now for several reasons.. first its afully programmable dfi ecm, and you retain your stock ecu in order to control less vital functions such as a/c, your fans, guages, etc..
If any of you read turbo magazine, they put in the haltech system into their turbo 2.5rs impreza...