I have apexi n1 exhaust on my car, and it sounds sweet, deep not crazy loud and nice power gains and sounds nice, as far as the headers u should be fine, unless u get the race jdm style one or whatever they call it.. but with 4-1 SS u should just bolt up fine if u get the right model and year for your car, and i believe u can run the exhuast for the 97/98 or 2000/2001 same thing (not a 100% sure) and with N1 u can run with forced induction or NA.