chu_rulz- this is a mission, engine alone will set you back from $6500, then you need a rb25 gearbox to run it in rear wheel drive only about $2000/guesstament, drive shaft, diff $??, fuel pump $450, gtr fmic and custom piping $1500, a serious brake upgrade lets say $3-4000 custom job, new 3" exhaust dump pipe back $1500, good syspension may be tag on another $1000+ to the brake upgrade as these two may go hand in hand and don't forget unless your doing all this your self you'll be paying someone to do it for you$$$ lifes a bitch!
In the long run if you do it all right the first time you'll have one of the fastest cars, after just a ecu mod or swap, in the skyline family!
have you got the latest zoom with the r31 on the cover, if not i'll scan it and pm it to you as the r31 has done a rb26 swap!