I set my turbo (hx35) to 30psi, and i use stock head bolts and gasket. The gasket is a metal gasket, elring or something like that. haven't have any problems in the past 10000 miles
The most important thing, as said before, is to warm up the engine before going crazy with the boost, and cool it down before turning it off. But that's a "problem" any kind of bolts or gaskets can't fix. Even if the gasket survives the abuse, the head itself don't.