I don't have much information about the MCP brakes. However, I believe you should always run as much rotor as you can get, which these setups provide. The only thing is you will need to be handy with a welder when attaching a mounting plate for the calipers.
I like the Hegar and EC front brakes because they are directly bolted on without any issues, and can accept 3-3.25" backspaced wheels, the Van-K two piece wheels make them a cinch, which is good if you are concerned about scrub radius.
I think on the Hegar caliper the piston is a little bit larger which makes for a bit more braking effort. A simple change of the clevis mounting point on the brake pedal will fix that.
The EC calipers have out of the box great stopping power, but the pads and rotors have a very limited lifespan. If you purchase the EC calipers, go ahead and purchase Hegar pads and rotors. I have been running the same set of Hegar pads and rotors for nearly three years.