Specifications:
Front Size: 35mm / Front Rate: 1340 lbs/in [40% stiffer than stock]
Rear Size: 29mm / Rear Rate: 685 lbs/in [135% stiffer than stock] 810 lbs/in [175% stiffer than stock] 970 lbs/in [230% stiffer than stock]
As for end links, if you are in the Northern climes, I would suggest the Whiteline product, because the rod ends are more sealed against the elements:
Whiteline Rear Sway Bar End Links - Nissan 350Z 370Z / Infiniti G35 G37 Q40 Q60 KLC141 - Concept Z Performance
Whiteline Front Sway Bar Endlinks - NIssan 370Z / Infiniti G35 G37 Q40 Q50 Q60 Q70 M37 M56 RWD KLC204 - Concept Z Performance
Note: The front end links need a longer stud to pass through the lower control arm, and the SPL front end links spec'd for the front Q60 AWD were even length studs and the center-to-center distance of the studs was longer than the stock end links. My shop "made them work" (removed the conical spacer(s)), but my front (stock) sway bar now sits quite low, which is caused by lowering the car 1", but also because the center-to-center distance of the SPL end link was longer, too. Bottom line, when I upgrade to the Hotchkis sway bars, I'll be ordering the Whiteline end links for the front sway bar.