It really does not matter where the grounding is run to as all grounding goes to the same place. Since you will be using cable which contains the ungrounded(hot), grounded("neutral"), and grounding conductors it stands to reason that all will be run from the same source, ie the switch box, wherever it is located. Even if you are using conduit it is necessary to run ungrounded, grounding, and grounded conductors together you cannot just run a single hot conductor in a conduit without its accompanying neutral.
I prefer to use GFCI receptacles as they tend to be closer to where you are working when one pops, but the advantage of using a breaker is that it is protected from the weather and abuse so they tend to last longer. Just use whichever is in a more convenient location relative to where the circuit will be used.