The easiest swap is 65 – 69 Lincoln spindles, rotors, calipers, master cylinder, etc. It’s the route I would go if I were converting your car. The factory discs have big 4 piston Kelsey Hayes calipers and stops one of these cars with ease. If you go that route get the 66 – 69 booster, master cylinder, and proportioning valve. The 65 still used a single reservoir master cylinder.
GearHead Engineering offers a kit for $845 that includes everything. abspowerbrake.com also offers a kit but the price is not listed on their website. I have no experience with this kit but I’ve heard through the grapevine that it might not stop as well as using factory pieces since it uses a smaller floating caliper based off GM parts.
You might be able to swap something from a later model car, but I doubt anything as new a a Crown Victoria would work. Perhaps an early 70s Lincoln or large Mercury setup would work. I know I used 69 Country Squire discs on a 64 Galaxie I owned years ago.
Resistance is Futile.