Regarding the callipers, I was thinking about opposing cylinder callipers rather than the single sided one's fitted. If I were looking to improve my brakes I would look to motorcycle callipers probably 4 pots on the front and proper 2 pots on the rear, back in my early years and tuning cars it was always desirable to have apposing pistons with the body made in one piece for no flex and a hard pedal as far as I know is a good thing to have, not only are the standard one's very basic that design will flex like a pig which is no good if you want powerful brakes (just my thoughts)