Dave,
I've even fitted those on my GT-R, Eibach are really good Had those on 350z and 370z. Do a bit of reading in how to adjust it, but you can start from the softest setting on both front and rear and go from there, depending on how you want the car, tail happy or lots of grip.
You could also change the drop links, unfortunately there is no cheap version available for the 370z, Whiteline only does the rear droplinks, although they told me @ SEMA that they had the prototype for a long time. The only other company that does the full set of drop links is the top of the range SPL.
Prices here:
http://www.torqen.uk/370z/suspension/swaybars/1348-370z-eibach-front-and-rear-sway-bars-32mm29mm-6393320.html
http://www.torqen.uk/370z/suspension/arms-links/18-370z-spl-pro-front-sway-bar-end-links-spl-fe-z34.html
http://www.torqen.uk/370z/suspension/arms-links/19-370z-spl-pro-rear-end-links-spl-re-z33.html
The front it's quite easy to do, well, easy on the ramp, but should be OK at home on axle stands if you have the right tools and patience. The rear is a bit more difficult, as you need to take the exhaust and the W brace off to slide the ARB in.
Have a quick look here regarding the setting the droplinks: http://www.splparts.com/content/SPLREZ33.pdf
Hope this helps!
Adrian