I use 10-52s in standard, but the larger you go, the less brilliant harmonics you get coming off the string. Too large and you'll really dull down the sound of your instrument.
I set my guitars up so that the nut slot is cut as low as possible - literally can't fit a rizla between the first fret and the string, the neck is kept completely straight, and the action is controlled by the bridge. It's odd at first, because even with the action stupidly low, there is no fret buzz, and I pick pretty damn hard.