it really depends. what's your budget? are you building your car as a driver or is there a specific goal or intended driving purpose-- ie. a burger cruiser is gonna be okay with entry level brakes where as a car set up for road racing will need something a little more robust.
there's many different ways to approach this. you can go with factory upgrades, a full aftermarket kit, or a mix and match of some factory pieces and some aftermarket pieces.
just remember, the whole thing has to work as a system. you can just throw parts around willy-nilly and hope for great results. upgrading brakes generally means upgrading other parts of the suspension and undercarriage as well.
