I've installed a booster and dual res master under the floor, but it wasn't a kit, I fabbed my own mounting bracket. I got a booster from a 70 C10 and a rebuilt master for the same, with drum/drum brakes. For the wheel cylinders go to a CarQuest or NAPA parts store. If they don't stock them, they can get them the next day,
Scott

Scott Ward

2 1948 1.5-ton Loadmasters
The red one and The snow pusher
1 1950 3100
1 1955.1 Chevy 6500
1 1954 Chevy 6500 2-Ton
1 1955 1st Series COE 5700
1 1963 K20 (454)
1 1964 C10 (350)
1 1951 1.5-ton Dump Truck
1953 and a 1956 Ford F800

Raising a teenager is like trying to nail Jello to a tree!