I know this has been talked about before, but I figured I'd pass this deal on to others. Roush has pairs of 2011+ calipers and brackets available for $75 shipped, and rotors for $50 shipped. This allows you to go from the stock 12.4 inch rotor to the 2011+ stock 13.2 inch rotor. You can reuse your own calipers and pads if you wish. The brackets alone are worth more than the $75 I paid. My calipers are at 110k miles, so I think it will be worthwhile to replace them as well. This is also a great way to get stuff powder coated or painted without down time.
2011 2012 Ford Mustang GT Front Brake Caliper Set 2 Factory Take Off | eBay
And rotors for $50
2011 2012 Ford Mustang 13 2" GT Front Brake Rotors Set Factory Take Off | eBay