i personally chose a no-frills mccarty over an artist package custom for the really warm tone..plus it has a coil split on the tone knob. i've never played a singlecut so i can't say anything about them, but i love the way the doublecuts hang on a strap, and every doublecut i've played has a HUGE sound. the mccarty has a much more vintage sound than the standard and custom, which i think are better for slightly heavier music. my favorite so far, however, is the mccarty soapbar. biggest sounding soapbar pickups i've ever heard, nothing even comes close for me, and i think its the most versatile.
either way, every single american prs is an amazing instrument. for clean stuff, i'd definitely recommend a mccarty with hums or soaps. keep in mind, too, that different prs models have different necks. the mccarty comes with a "wide fat" neck, which is a little more chunky than the standard or custom. you could also think about getting a standard/custom with mccarty electronics, which they make but davis might not have stock of.