2001semax

Ok guys i know this subject had been asked millions of times but the damn search dont work so i gotta bother u guys on more time.. i want to get a intake , y-pipe and b-pipe i want to leave the stock mufler cause i dont want my car too loud.
i am thingking of going with the prcai cattman y and b pipe.
what kinda gains do i expect to see on a 2001se auto?... will i get power from low end to high end . or do i compromise low end for high end or vise versa( hope thats not confusing)...and also wheres a good place to getall there components.
also if you guys have any other suggestions or combinations that would prove better performance im all ears. i wanna do this very soon.
thanks