for the Z get the space gray with red, as far as the black choices if you do decide on that go with the metallic black. bottom line get ready for alotofmuthafuckin attention!!!
http://e89.zpost.com/forums/showthread.php?t=200385
but the undisputed best color combo is white with red interior, but i would only get that if you dress like a dolce and gabbana model 24/7
BTW, the woods look shitty in all pics. if you can compare some at the dealership it'd be better than relying on pics. having said that if you go with Red interior only aluminum looks good with it