Seems easier to drill a hole in the valve cover, you know it works, the factory did it that way! As HotRodLincoln mentionned, drill at the back end of the valve cover, so it is somewhat hidden and does not fully "ruin" (esthetically) your valve cover.
Then, still to keep it simple and the way the factory did it because it works, take the vapours to the air cleaner, "before" the air filter.
It works, it is simple and pretty discreet.
