Well, while driving Rusty today...last minute present hauling

...I pressed the brakes due to traffic coming to a stop, and the pedal sank to the floor.

I was able to quickly pump the brakes and get it to stop. Based on that and signs of brake fluid on the floor in the cab, I assume the master cylinder needs replacing.
So, is there a cost effective way to add a dual master cylinder...and power booster? When adding a dual MC, are there pre-made brake lines, proportioning valve, etc. that are cost effective to acquire?