I used the 0.75 ore (I think) that Marlin supplied for our M3 E36 Sportster. Then got a hose made by HEL for it, and it works OK. It is a pretty hard push (you do get used to it), and the bite point is in what you would regard as a 'normal' position. Haven't reinforced the pedal box, but think after reading other comments maybe I should have done! This can be a winter project, whilst the panels are off getting painted.
Hope that helps maybe!