Good night

I'm new here and have difficulty writing English, so I use an online translator. I apologize.

I am possessed of an Escort RS Turbo S2 1988, and I'm changing the braking system;
Front -> Disks 283mm sierra cosworth 2wd + 4wd calipers
Rear -> 273 discs and calipers sierra 2wd

My questions are as follows: switch the master cylinder and a servo for a higher capacity?
Remove ABS? Yes, not ....

What do you advise in this case?

I thank you for your willingness to help me.

Thanks