Here's what to do, on a smallish budget;
SARD 700cc injectors or Injector Dynamics 800/1000's
Bosch 044 if your fuel pump is old and tired
Good clutch (personal preference is nismo twin plate but thats $2k)
S tune Nismo filter in stock airbox
Garrett -7's at 20-22psi
PFC Djetro (it doesnt use AFM's so that saves you from buying Z32's)
R34GTR dumps
Pretty much any aftermarket front pipes aswel as a cat back system (just get a 3.5' system)
Good flowing cat (or none, depends on if the car has rego)
Profec B spec 2 boost controller
That formula has seen 300rwkw on a few Sydney cars lately and is a really basic but quick setup. Cams add midrange, well worth it, but it all comes down to cost. If you want to post up what you've got etc surely someone here can/will help you in the right direction and help you to not buy useless mods.
EDIT: That above list sets you up for bigger power later if you choose to go that way, it will be a turbo change and some engine hardwear and you'll be closer to 400kw