What sort of power are you looking for mate? If you are happy with 200-215rwkw then just bolt on another stockie (make sure it has OP6 stamped on the ex housing, these are the VG30/R34 GTT turbos), if you want anything up to 250rwkw get you current one hiflowed so its bolts straight back in, looks stock and will make nice responsive power.
If you want anymore power then check out the RB25 power reults thread (stuck up the top of forced induction), this will give you an idea of what turbo (and other mods) you need to make the numbers.
nick