try www.centralfloridamotorsports.com, they have a new billet bypass valve that is a direct replacement for the stocker and its only $125. i dont know how good it is though.
If it's the black plastic Bosch, it's supposed to hold 12psi. I have the same one and I've pushed up to 21 through it at the track and 14-16 on the street daily. It stills sounds like it's still fine but I plan on getting the billet one soon.