cold air filters
Z32 AFM's
good exhaust
front mount? (maybe)
hi-flow turbos
power fc and boost controller
some nice suspension
a good clutch
fuel injectors, regulator & pump
good performance tuner
other misc bits n pieces like oil/air sep., cam gears, replace all belts, fluids, plugs, brake pads etc. with good stuff.
15 - 20grand for the above i rekon (realistically). should run 11's, i dont know, i dont own a gt-r or know anyone who has modded one.