Which mk1 fiesta master cylinder?

[andypg]

After 12 years building and upgrading my striker irs,ive decided to change the master cylinder.The reason for this is the pedal is too hard and i want a bit more travel.I'm using the master cylinder off of the sierra and want to change it to a fiesta mk1 one. The question is which one is best,the non servo one which has a 17.5 mm bore with push rod or the other one with a 19.05 bore? Or any other make,what are everyone using these days? Thanks,Andy.