master cylinder for stock front disc + empi rear discs

[mabbo]

i have just been playing around with the excel calculator Angelo Amato posted on another thread:

http://myweb.tiscali.co.uk/angeloamato/BIAS.xls

with 40mm front, 36mm rear and 19.06 master cylinder = ratio 1.235 to front
with 40mm front, 36mm rear and 23.81/19.06 master cylinder = ratio 0.791 to front
with 53.5mm front, 36mm rear and 23.81/19.06 master cylinder = ratio 1.415 to front
with 53.5mm front, 36mm rear and 19.06 master cylinder = ratio 2.209 to front.

what sort of ratio is acceptable? i assume from the list above 1.235 is the best, so maybe a stock 19.06/19.06 master cylinder would be best, or, the 20.64/20.64 would give the same ratio with a firmer pedal.

am i on the right track?
mabbo