I, too, would vote for the Cobalt wheel cylinders if keeping the original Bendix/Dunlop disc brakes. They are a better, more modern design than the originals.
I, personally, have converted my Studebakers to modern disc brakes, either Turner or Hot Rod & Brakes (have used both). The HR&B disc kit has gotten good reviews & costs $150 or so less than Turner's kit. Jim Turner now uses Chrysler minivan calipers in order to avoid the clearance issues the previous GM calipers sometimes had.
One note on rotors: I have just had to replace the rear rotors on my Olds Aurora due to rust (flunked Va inspection after only 1000 miles, 2 years). I'll never again buy non coated rotors. The coated ones cost more (20% ?), but I want to do my brake jobs only once. One can also paint rotors and I have done that.
So, the good news on supercharger colors is that you can paint yours either orange or black, whichever you prefer. I made a major mistake in having mine painted black.
--Dwight