I've been waiting for NISMO to come through for too long now... I have yet to see that NISMO Spoiler for sale anywhere. My recommend is to shop around and wait until one really strikes you.
As for the kit, the Buddy Club is a great kit (even though it's fibreglass) I ordered the VIS Octane myself (which is also a fiberglass Kit)
http://www.cardomain.com/member_page...=Nissan%20SE-R
To each their own, but I like either the Buddy Club or the Octane .... everything else I've seen is tastless IMO.