the easiest 2 options are:
1. Turbo your na motor, in which case look in the na section, as theres plenty of info on this and will work in the same way with your engine.
2. Go get a stagea engine, it will bolt straight in, you'll have the awd block, sump and diff ready to go. With this option you'll obviosuly have the much stronger rb25det
OR
build a rb30det, this is the most expensive route, but you'll have an extremely strong motor (once again plently of info, just search in the rb30 section in forced induction)
Choose which option you want to go (most likely the stagea engine, since its a balance between power and money), then search on the forum, theres plenty of info here