My Road Runner has manual drum brakes, all 4-corners. After being in storage for 21 years, the master cylinder is empty and rusted so I plan on a new mc, wheel cylinders, lines, etc.

Just to get the car mobile again, I'm using the local parts stores and getting what can be had from them.

Eventually I want to add disc brakes to the front. In an effort to plan ahead;
1. When I switch to disc brakes, will I have to change the master cylinder?
2. If I do have to change the master cylinder, can I install the one that is needed for disc brakes now and will it work with the drums?
3. Are manual disc brakes much more effective over drum if they aren't power disc brakes?

I used the forums search and couldn't find my answer.

Thanks for inputs!