Disc brake upgrade questions

Hey All,

I'm upgrading my brakes to front discs. Car is a 68 Val which had 9 in drums all the way around. The rears have been changed over to 11x2.5, while doing a 8.75 rear end swap.

The fronts are next. I have a 10 in. set up for the fronts including a late K member, late control arms, spindles etc. I also have a late master cylinder with the large resivoir for the disc end.

I do not have a late model stock proportioning valve from a 73-76 car. Do I even need it? Can I use one of those after market adjustable proportioning valves instead with the existing metering block?

If so, can someone recommend one? And where I would install it.

Am I forgetting anything else?

Thanks

CE