Forget about the short ram and bypass valve.. not only will those provide no performance gain, they will make the car run worse without custom tuning. A catback won't provide any performance gain either, but it won't hurt anything.
If it were me, I would take the money you were planning on spending on the SRI and BPV, and buy a turboback exhaust instead.
If it were me, I would take the money you were planning on spending on the SRI and BPV, and buy a turboback exhaust instead.