which master cylinder to run?

I used a later aluminum unit. There is lots of info out there on how to use one of these. At quick glance, this one article has some info:

http://www.moparaction.com/Tech/archive/disc-main.html

Also, Zippy - who I'm not sure is on this board or not, can help you with the adapter and can likely help you with the whole setup.

http://www.moparchat.com/forums/showthread.php?t=19201

Cheers!