[fwayne]

Regarding the bore size of the Master Cylinder. All things equal, a 1" MC will offer less brake pressure compared to driver effort than a 7/8". It's basic physics. When you compress Hydraulic Fluid It's the ratio of the input vs output. The smaller in diameter the input, the higher the pressure, but the tradeoff is the lower the volume for a given pedal travel.

So...Manual brakes tend to have smaller diameter Master Cylinders, while boosted versions can afford the larger version. Using the smaller diameter will require less pedal effort, but consequently more pedal travel. So go 7/8" for manual, 1" for boosted.

If you get it backward, you'll have a rock hard pedal, brakes will come on quickly but you'll have to stand on them to stop. If you get it backward in a boosted setup the pedal will be mushy or even hit the floor before brakes work.
Be careful matching to aftermarket calipers, they can vary wildly on caliper piston size or number of pistons, the ratio can get out of whack very easy.