1970 Camaro-Purpose Built Auto Cross

[71RS/SS396]

If you're going to do strictly auto-x then the C6 Z51 Kore 3 brakes are plenty of brake for that. I would stick with a floating caliper in the rear with a non floating axle to combat knock back.

The manual vs power is really a preference imo, I prefer power brakes because I find it easier to finesse the pedals when your not using so much leg effort on the brake pedal.