i can only recomend what i know and all i really know is what i have, however what i have sounds like the path your about to take.
in my 20 i have
new turbo (no point in sujjesting which one cos theirs pages of debate and it comes down to what u want, R33 turbo is the easiest way)
GTR injectors
GTR coilpacks
Z32 AFM
Nistune
FMIC
Dump/ exhaust
GTR BOV
044 fuel pump
at about 1bar i squeeze past 200rwkw and its comfortable but yeah the 20 needs to be wound up a bit before it boogies, but they just keep on reving.
feels good, great power after 3000rpm and pulls on and on and on....and on
i spent allot of time chasing down little vacuum leaks and cracked hoses.
spend some time doing this cos eventually you will find one little split, replace it and all of a sudden it all runs smooth as cream.
if the 20 isnt stone smooth then somethings not right. start pulling pipes, seals and joiners and see which ones have lost their flex and fall appart, when in doubt just replace their cheap.