You can either ring up GCG who's based in NSW to hi-flow an R34 GTT turbo for you or get a VG30 hi flow. Either these will be good. Between SAFC and E-manage, i'll go e-manage or even e-manage ultimate if they are compatible with auto.
Once you start changing the turbo, be sure to source out bigger injectors. Prob 480CC or better. Also remember injectors meant for the RB25DET in the R33 are different with those in the RB25DET NEO in your 34.
With injectors, you'll need a fuel pump. Either the Bosch 040 or Walbro fuel pump will do. FMIC will be the way to go as you'll more than likely go beyond 200rwkw soon. Once beyond 200rwkw, time to upgrade your stock clutch to something stronger.
Hope this helps.