65 Plymouth Valiant rebuilt OEM brake system what kind of fluid is best?

[WH23G3G]

I'm down to the last wheel on my 65 Valiant brake system. I decided to stick with the OEM braking system since I'm not going to upgrade the engine or transmission. It's just a 170 stock. It has manual 4 wheel drums, 9" drums all the way around. What I did is replace everything I could get. I replaced all wheel cylinders with new not rebuilt, new shoes, new spring hardware, new adjuster kits, new rubber brake hoses, new Bendix brake drums, new steel brake lines from Right stuff, and for now I have a Cardone remanufactured original single port master cylinder still in the box. I'm going to go for a new one from Dorman since it comes with the pedal return spring. So the only pieces left are the junction block on the front and the tee on the rear which I removed and cleaned thoroughly. I'll have to take it somewhere to get the emergency brake adjusted properly since the adjuster on the equalizer is rusted and just spins when you loosen it. So knowing all that and before I add fluid which fluid is recommended? I know this is not the most trusted braking system for a almost 50 yr old car but I figure it made it this far without any disasters. Should I go with a silicone fluid or a synthetic brake fluid? Is any one going to keep the rubber seals protected better against leaking than the other?

[A383Wing]

I'm still running Dot 3 or 4 in all my cars...unless you plan on driving the car hard or road rallying it, the Dot 3 or 4 has been proven for years

my opinion, others may vary.....