If you do not track your car often the slotted and drilled is good enough just for DD and some spirited driving.
The drilled rotors tends to crack on excessive track use. But I think you dont intend to do that much track time on your Z.
Mine is sports package. I slowly modded my car as Im the only bread winner in the family. I started with suspension and brakes upgrade before I went to interior and exterior upgrade. Here is a picture of my Z now.
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