I just started down this road myself, and I agree the 300ZX looks good as it is, it is a 14 year old car so I am going to live with the chips and couple of door dings the only thing I might do is replace the front bumper as it is a little beat up and I might go with stock, I just waxed it.
Before I go down the engine mods I am refreshing the car by replacing age related items to help it run better and ride better, such items like PCV/EGR/Cleaning TB and connections, replacing suspension bushings/shocks and the first mods are springs and swaybars, then will be stage 3 (Intake/ASH ECU/Exhaust/Boost Controller)