I'd seriously recommend reviewing some of Gsedan35's post history, on here and on my350z. The guy has been through more suspension setups than any sane person would attempt, outside of being an engineer at a suspension components company. IIRC, he's quickly approaching 100 discreet configurations, not to mention the many times he's personally dyno'd various shocks/struts.

Here's one of his posts on my350z.com from May of this year where he shares some of his expertise: http://my350z.com/forum/5694684-post18.html

And then here's his authoritative reference on aftermarket spring, shock, and coilover rates:
https://g35driver.com/forums/brakes-suspension/65190-g35-350z-aftermarket-coilover-springs-shocks-spec-s-w-updates.html