I'm contemplating a similar setup as this @RobPhoboS
I'm sold on the Tein S springs as limited drop, previous 350z with these handled much better than my current one (that also has twice the miles and not wearing MPSS, so not a great comparison but feels more unstable, will be doing tyres asap, may be try the GYSS ;)
Other options to B6 seem to be Tokico, KYB or even Tein EnduraPro (which are also excellent value)
Did you stick with this setup or did you fit some ARBs / coilovers later on?