Yup, your car is a very nice starting point and has a lot of potential.
You probably won't know what spacer you will need until you get the drums drilled and the MaXX struts installed. Someone may know if assuming the temporary drum brakes and similar disk brakes are the same if you could tell us the wheel's offset and width are.
I have MaXX struts on my '71. I think you will be pleased.
I can't help you with the master cylinder question. You might try a search on what others did with 944 brakes. If they went Porsche with the m/c, you might want to follow suit.
Keep us posted.
