I've been running 14" Brembo monoblock front brakes for 8 years and this past week I finally moved to 14" rear brakes.
I engineered a bracket to fit 2013 GT500 rear rotors on the car and use them with the stock caliper. When I calculated the bias, I'm around 70/30 with my new setup compared to 76/24 with 14" fronts and stock rears. I'll try to make a detailed post later today! Here are pictures of my front and rear brakes.
I didn't want to go the FTBR route on brakes as that locks me in to their custom rotors. This way I can stick with factory wear items.
Great idea and results. I also have concerns about being limited to a custom rotor as well rather than off the shelf bits.