I won this at an event this year and already have one...so, here ya go.
They're $190 + S&H new from Z1 Motorsports.
370Z / G37 AMS Lightweight Pulley
It's black, made by AMS and comes w/o drive belts. As it's NOT an under-drive, your stock belts may be used.
PM me if interested, will do PayPal.
Chris