Mike;
The front brake disks are the same for both the Sedan (N 600) and Coupe (Z600) part number 45251-568-600. Unless your disks are grooved or thin from over cutting I have had good results from smoothing them out with 80 grit disc grinder. Normally just to remove the rust from them lying around. Also most large brake shops have the capability of putting new pads onto your old brake pads and often using a better quality material.
Bill