I have a 03 Sedan with Regular suspension NON SPORT and was wondering if I should go with the 350z suspension (shocks,springs) or just springs. Or just get some Eibach Prokit springs? I have 20 inch rims that is 8.5 wide wrapped in 245/35 tires will this confict with the lowering?

 

Eibach should work but I recommend the Nismo S-tune for a sedan. It would drop only by 3/4" and provide a coupes sport susp ride. Plus the shocks are matched to the springs and the matching sway bars would make it a sweet handling sedan. The bonus is the factory warrenty offered on Nismo s-tune parts.

 

I'd go for the 350z RSRs. They drop the coupe down about ~1.2in. I'm not too sure how much drop there will be on the sedan though. My guess is around the ~1.5in range? If that's too much you can get the g35 coupe springs that will lower your car ~.6in + the additional drop since you have a sedan.