what do you have a stock engine???
1)high flow cat and 2.5-3"zorst
2)pod + CAI(cold air intake)or Rb20 air flow meter or if you can afford it Z32 air flow meter
3)T28 or or better GT2540orGT2830
4)pistons can handle 16-18 18 for short spurts wouldnt drive will 18psi daliy maybe just a race here or there
5)GTR 444cc straight fit or nippon 460cc
6)maybe cam gears mild head work JNH offer head work with a 40%increase of power without other mods
7)if your up to here you got to much money and should give me some
professional build upto $10k good for 400kw
all of these mods upto 6 should give near to 200kw but internals can take 300hp before problems check out zoom for the ca18 article
have fun
4got big FMIC and BOV