Just curious on why you want to run massive rear brakes?
You are probably going to have to custom make the parts. You'll need a 2nd brake master cylinder, new brake lines, probably need to run a hydraulic handbrake since an aftermarket caliper isn't going to have a handbrake cable attachment (especially if its going to be dual piston which all large rotor setups are).
The factory lines and master cylinder is only going to put about 10% of braking to the rear, and if you oversize your rear brakes or try running larger calipers then you will be reducing your rear brake output to 2 or 3% from 10%, not to mention larger rotor means more rotating mass which means increased braking distance.
What other brake modifications have you done? If your running stock pads I would highly recommend that you upgrade your pads to the Hawk HPS or HP Plus line before you try any fancy caliper modification.
Also do not waste your money on the rotors. Buy the cheapest Autoparts Store rotors you can. I run 30$ Rotors with my Hawk HP Plus and its more than enough. I've done the ITR Caliper / Lude Disc Upgrade, and I don't ever use more than 60% of my brakes at the track.
