hmm..out of that list, i would go with HKS out of that list...borla is great i you drive a mustang or camaro, but the non-V8 systems i have seen really arent impressive, no offense to anyone who has that system. i have limited experience with magnaflow, but i met a kid who helped to develop the system for one of my cars, and he was enough of a tool that i wouldnt buy the system...
HKS on the other hand, is the chosen manufacturer for alot of the major overseas companies like Nissan of Japan, and Toyota, and HKS makes alot of their own forced induction kits, so they know their stuff.