what master cylinder for disk/disk set up?

I have tried 3 different NON power master cylinders in the past 2 weeks, all with a different feel. The absolute WORST was a large bore unit 1 5/32". Very short pedal travel, rock hard pedal and the car wouldn't even skid on ice. Next was a 75 Dart Disc/drum unit, one inch bore. It was a little better, but still not quite right. The one in my car now is a 15/16" from Dr Diff. While the car still doesn't stop as quickly as I'd prefer, it is MUCH better than the large bore M/C. I can testify firsthand to the theory of bore size in relation to pedal effort and effectiveness.