if you want to turbo it and do it "factory":

buy off a vxr corsa:

manifold, turbo, down pipe/cat, intake (not reeded entirely), maf, injectors, and computer.

then go get a head space made to match the oem compression ratio of the vxr.

spend a little extra before it get shipped and have the ecu flashed before hand.

with current exchange rates this could cost as little $2000.

i can tell your still "new" to turbos being you think the intercooler is absolutely necessary. you only need to go to an intercooler once you have heat soaked air getting to the throttle body. which does occur quickly, but if your only running a few lbs of boost, and are not tuned, the intercooler is almost overkill. I have seen plenty of non intercooler set ups work very well.