(Photo Credit: 370zblog, Nissan North America, NML)
JDM:
http://www.nissan.co.jp/OPTIONAL-PARTS/NISMO/
USDM:
http://www.nissanusa.com/microsite/nismo/?intcmp=NismoZ.Promo.ZCoupe.Home.P2
Front
JDM S-Tune:

USDM NISMO 370Z:

The fangs are 'gone' with the USDM version, which achieves a cleaner look for those who didn't quite appreciate the 370Z's 'toothy' look.
Back:
JDM S-Tune:

USDM NISMO 370Z:

SIDE:
JDM:

USDM:

Close-up of JDM S-Tune rims:

Close-up of the Nismo USA rims:

USDM NISMO Gauges:

I think it's interesting that NNA SVG (Specialty Vehicles Group) is at least attempting to build up the NISMO brand into a strong contender that (hopefully) can rival the kind of appeal Mugen has achieved amongst the Honda owners.
The Z looks continue to polarise opinion, but it's heartening to note that NNA has collaborated with Autech to create a look that addresses some of the points of contention, one being the 'fangs' that were retained on the JDM S-Tune package and the rather old-school alloy design of the S-Tune.
Apart from chassis/suspension upgrades, the USDM Nismo 370Z is available as a complete car and features close ratio 6spd M/T transmission and ECU revisions to further boost engine output numbers to 350bhp and 374Nm.
More 370Z here:
http://m0t0rhead.blogspot.com/2009/03/nissan-370z-at.html
http://m0t0rhead.blogspot.com/2009/03/blog-post.html