Captain Smiley,
An NDB approach is just that, an approach to an airport. It may or may not be a runway approach and line up with a runway. Otherwise circling is required. To (legally) fly any approach an instrument rating is required.
A cloud break proceedure is just that - a way to get below cloud. Enroute instrument rating holders are able to fly cloud break but not approaches. Naturally the minima are higher for cloud break.
In OZ there are cloud break proceedures not even at an airport.