+1 for the cleaning the idle gear
clean it with carby cleaner, just don't break the gasket
also, if your gonna get a z32 afm, you will need a tune
i'd say go nistune, but i think for what your looking to do, you probably won't need a nistune
i'd do:
Hypergear highflow or atr43 (best to speak with them about what you want from it)
Injectors
z32
Deatchworks fuel pump
Nistune +tune
if your careful you can acquire parts that are interchangeable, run a chunk of boost down the 20 and when that goes replace it with a 25