I was looking at suspension setups a few months ago and basically I am ending up with stick with the Nismo springs or doing something custom which I am not willing to do.
Regular
F - 7.5kgf/mm (419lbs/inch)
R - 8.1kgf/mm (453lbs/inch)
Nismo
F - 8.6kgf/mm (480lbs/inch)
R - 9.3kgf/mm (520lbs/inch)
Tein S-tech
F 8.5kg (-0.9")
R 9.4kg (-0.7")
Eibach pro kit
F 8.6kg (-0.9")
R 9.5kg (-0.8")
H&R Sport
F ? (-1.3")
R ? (1.0")
Tanabe NF210
F 5.9kg (-0.8")
R 6.8kg (-1.0")
Tanabe GF210
F 8.8kg (-0.8")
R 9.1kg (-1.0")
Swift Spec-R
F 10.0kg (-1.2")
R 10.5kg (-1.0")
Spring Rates