Zane,
You have a BEAUTIFUL car. Cherish it !
I converted the front brakes on my '59 100-6 to stock Healey front discs, I believe from a 60 MK I. They have pleanty of "stop".
Although you won't have room, I also converted to a Ford dual piston (disc/drum) master cylinder.
You could easily install an adjustable proportioning valve for the rear drums.
Tim