I attempted to calculate out a good fit out of the gate for my manual setup. It is a delicate balance of stroke vs force.

My first m/c was a 7/8", the feel was great but the stroke made me concerned, it just took too much pedal to dab the brake to slow the car quickly on the street. I have a 15/16, which is better, but I'd entertain a 1" test drive if the m/c showed up on my front porch. Everyone is going to have a different opinion on what is "right", or "best".