I'm chasing the similar power gains, and have no desire to f**k with internals.
The shopping list.
Full Catback Exhaust + Dump pipe
Hi-Flow Cat
FMIC
K&N Airfilter or Pod, with Cold Air Induction snorkel
Fuel Pump (think Bosch 040 or 044)
Coil Pack
PowerFC (or similar)
Boost Controller (Electronic is easier)
Z32 AFM
Cams (Tomei for example)
Injectors (shoot for 80% duty with your target output, that way something can fail and you wont blow your engine)
HiFlow RB25 Turbo
Thats roughly the order too.
All that, plus a tune by someone who knows whats up, you're looking at 250-280rwkw, every bit as responsive as the original turbo, and very very quick. (n.b this is for an RB25, RB20 you'd probably need to massage a little more)