don't forget, a manual brake setup uses a different pedal ratio than a power setup, with 6 or 7 to one being about ideal.
then as said, a small[er] master cylinder bore, and larger [meaning more piston area] caliper size.
however, with that said, it's a balancing act. all of the above need to work as a unit to get the best results.
reading the "brake" sticky by member feets is well worthwhile, and can shed some light on things one may not have thought of.