Jason is right ! 5psi on a non intercooled system is a max!!
w/o the intercooler the charged air is pretty damn hot. One thing that you might wanna consider is setting up some sort of "cold air" intake that goes into the bumper of the car, that should drop the temp by at least 80 deg. depending on outside temps.

As for the intercooler setup, Spearco is the shit when it comes to intercoolers, not that apex is not good. But for around $500 you can pick up a nice Spearco intercooler.

good luck !
-= RS Turbo=-