I used Hydratech booster for mine. Great to deal with. Yes pedal is touchy, but you get used to it. Mine is on a 64 Lemans front disc rear drum system.
If your just streeting the car these will be fine. Is comes in different finish, I got the show finish one but was not as nice as I thought it should be.
These are brand new, not rebuilt units.
https://www.hydratechbraking.com/GM_A_Body.html