I don't know if any came with a 7/8, you may have to find an aftermarket master from Wilwood, Baer, ssbc, etc.

If the 7/8 is too soft of a pedal or doesn't have enough stroke, then a 15/16 may fit the bill. The problem with all the brake calculations is that it's nearly impossible to calculate actual pedal feel while stopping the car, to know if it's what you want/like; and you end up trying a few different things until you find the perfect combo