just got my set of N1's installed. found them on the forums. they set me back approx $3500+ which includes N1's, installation and tune. made 283rwkw @ 20psi.
max power from a set of N1's are apparently 300rwkw
previous mods were Z32's, cam gears, pfc, trust cat back, bigger in-tank fuel pump @ 1 bar making 210rwkw
i would also recommend going the bigger turbo route if you can afford it. the difference in power is amazing.