Brian, you don't tell us what kind of car you have so it's hard to give much good blind advice...however, here goes.
My 17 year old son's 57 Belair 2dr Sedan has the manual disc brakes/drum combo. As I have never owned a car with power brakes myself (my wife's cars don't count). I have never had any trouble driving it or stopping it. My son has no trouble, either, probably because he was put in it and there it was...learn the system! He has no complaint about either the manual steering or brakes.
(PS, the reason the car has no power is because the guy who had it before was freaked out by the $200 difference in the manual or power conversions.)