Basicaly what i want to do is put 2 piston calipers on my rear brakes, like the calipers on my front brakes. Does any one know of a kit for this or a good way to rig it up?

 

I don't really see that there would be too much advantage in this under normal driving conditions. Your front brakes do 60-70% of the braking anyways, and "rigging" up on brakes is usually not a good idea. I've not even seen if anyone makes them anyways.