The real question here is: are you going to be doing some sort of competitive driving where big huge brakes are necessary? Good pads, good fluid and stainless lines are plenty to make a noticeable increase in braking capacity over stock. Nice tires also make a big differene.

I ask this question because if you are planning on getting any sort of kit beyond same-as-stock-size rotors, nice pads, stainless lines and good fluid, you will be bumped out of STS which is the class you would be in SCCA autocross. If you're just getting it to say you have big brakes, that's overkill.