from what i´ve heard, the painkillers are rediculously clear, with a very "chuggachugga" kind of sound, and lots of articulation. the other pickup i´ve heard recommended for mahogany is the Cold Sweat.
i´m trying to choose pickups myself :P
but to break things down, what you want is a high-mids oriented, tight-sounding (clear and bright) pickup, to "balance" the low tuning and the fact that the body is mahogany (which has lots of low mids. it´s a dark sounding wood)