you''ll feel better engine response, pick-up wise not that much different...auto maa...
It might be a little hard sourcing a complete stock EK9 piping...u can "rojak" with aftermarkets piping for same effect...
For B16A Auto piping setup, I recommend using stock muffler; EG6/EK9/DC2 or mugen twin loop..if you use loud racing type mufflers your low revs will suffer..not good for daily driving..also "kantoi" your car auto...haha
Heres a link about B16a auto piping discussed already :
http://www.zerotohundred.com/newfor...ust-mod-really-confused-help.html#post4297129