I cant keep upper intake gaskets from leaking or blowing out I dont know my boost but have a boost gauge on its way. Is there a good gasket that wont blow out or should I use studs

Make sure you clean the surfaces off really good and dry. Torque the bolts to 15 ft./lbs. IIRC. I always installed mine with a thin layer of RTV sealant on each side too, and let dry 24 hours.

How much boost can the stock heads and intake take? Is 18 psi to much?

Well as far as the heads themselves and the intake themselves, no it is not too much.