New Clutch dilemma

Quicksilvers

You should go with the Z1 Motorsports standard full face clutch and flywheel combo which comes with a new pilot bearing. I would not go with the Stillen clutch and flywheel unless you plan on going with forced induction sometime in the future. Everytime you install a new clutch you must install a new flywheel or resurface your current flywheel if it is not damaged or showing major signs of wear. In your case I recommend installing a new flywheel with your new clutch. Shops are generally less expensive on labor than the Nissan dealership service department. Make sure you do the proper break in with your new clutch.