Something that no one has yet mentioned, Gary, but is pertinent to the discussion is that you mentioned that you started driving in 1980 so you probably have never driven a car without power brakes before the Speedster. That makes a huge difference in foot effort required to stop your car. None of our cars (except the SAS versions) have power braking so while going to disk brakes all around will certainly stop you straighter (and probably a bit shorter) they'll never stop you the same as if you had power brakes.
While it is possible to add a vacuum hydrovac brake booster to our cars, it remains a major PITA and I only know of two people world wide who have done it. The point is, you can add disks to the rear of your Speedster, but you'll never get the softer, more positive brake pedal pressure you get on modern cars.