Dude, you'd be mad not to get a G35 Vortech Kit out of the US. I got mine from Performancefactory.com - cost me about $6k landed when the dollar was good. Came with everything, plug and play. Spent about 14hr fitting it myself, ECU worked like a charm and after a minor touch up tune ($200) i spun up 360RWHP with my 5AT drivetrain. ECU is easy to tune yourself/tuner on dyno. Cannot complain, easy to follow instructions, easy to upgrade the pulley for more boost etc - car response was phenominal!
PM me for more info if you want!
JK