with you dizzy. It is my understanding that the Nismo was only offered in Canada for one model year, the 2011 and has since been discontinued for us up here......
OP if you are thinking of modding it in the future I would go with a fully loaded Z and then just add to it from there. If you are planning a track car I would buy the most base possible and add everything from that platform. Just depends which end of ownership you see yourself in IMO. That's how I made my decision planned on street use with mods to taste so I bought the Canadian 40th and will play with it from there.
Have fun and good luck!