I was wondering if I switch my single bowl master cylinder to a dual for safety, do I need to use a porportioning valve? Also what do you suggest I get for master cylinder? I am staying with the drums for now. Have other things I want to do first.

 

All 1967 and later cars/trucks have dual master cylinders and this:

A brake differential proportioning valve.

There are different valves, it depends on whether the vehicle has disc brakes or not.