In my opinion, there is VERY LITTLE you can do to improve braking by a large percentage when continuing to use OEM sized rotors and calipers. When confined to the OEM size, you can only move to better materials.... which offer some performance benefit to braking, but not a huge difference over OEM. I always use Centric coated rotors and Akebono pads. There are better pads out there, but only marginally. If you aren't putting it on a track and running your brakes really hot, moving to more expensive/exotic drilled/slotted rotors and high end pads will not make much difference. I have used the Z36 kits from PowerStop in the past, and I didn't see or feel much difference, even when getting the brakes hot.