Since you are adding some serious HP to your car should you not upgrade the brakes now? Instead of wasting money on pads and labor. I just spent $5 at the junk yard buying used pads till I can get my 500E brakes on. (waiting for the rims! & SS Brake lines)

If you buy good pads for the stock caliper and disc. It will stop but not match your performance level. I took my car on a drive and lost the stock brakes after a few turns. Even with Carbon Kevlar pads I would maybe make a few more turns. Can't beat upgrading the rotor size and venting.