oh i forgot to add clutch as the stocker will most likely die somewhere between 180-200rwkw.
walbro gs342,bosch 040,nismo - take your pick. some ppl have had walbro fail - there are fake ones around. nismo is twice the price but direct fit and ists nismo so its heaps cool.
you just need the exhaust cam gear to keep vct(variable cam timing). i havent done mine but i belive it relates to faster spooling than outright kw gains.
you will then really need a tune to make sure everything is running ok (safc/remap). id consider all that stage 1 mods.
then stage 2 would be
PFC/Vipec/Nistune(z32board) - ecu upgrade does wonders for stage 1 mods as well.
injectors
turbo - depending on what you want highflow stock/2530/2835/3076 - the options are endless but it depends what goal you want - power or response.
And would you believe i learnt all that reading SAU:)
cheers Rich