I have an h23a w/ an AEM CAI. I am adding an AEM Pulley and DC CC Headers soon. I am also adding a cutout valve to allow me to bypass the cat and muffler. I will be pushing the maximum high end power from the exhaust using the bypass valve, but it has poor power until you hit 3500rpm.

Anyway my question is what is the best exhaust combinitation to get maximum low end power (thru 3500rpm) when i use the cutout, and decent mid-high end power for when I dont use the cutout for the money? I also dont want much sound from the muffler since the intake/header already makes lots of sound.

My options are:
1) Stock Piping, Universal performance muffler.
2) Stock Muffler, Custom Piping (what size is good?).
3) custom piping and muffler.
4) stock muffler, stock piping.