Up to 10psi is in the Supposed safety zone for the stock turbo but also about all the ECU will handle before it gets all Rich & Retarded...
Get yourself a Just Jap Bellmouth Dump / Frontpipe, 3" Cat, some sort of Intercooler upgrade (either Frontmount or an R34 GTT sidemount) and get an R32 GTS-t 10psi Actuator. (or use the boost controller if you wish)