What Disc Brakes to Use

1 sure way to decrease pedal effort is to put in a M/C with a smaller bore. The down side is more pedal travel.
I would keep the brakes u have and try a M/C with a smaller bore and then look thru the catalogs for some decent pads. The big advantage to the GM calipers is there are tons of "performance pads" avalable. The performance friction #83 compound comes to mind Its got great cold torque and dosent fade with heat.