You definitely want potted pickups for high-gain rock/metal music (I can't comment on djent, I am about 20 years too old for that :P ).
I don't want to get too much into the pickup-choice advice because I don't know the musical style, but I can say the Cold Sweat set has a very nice contrast between neck and bridge pickups - the bridge is tight and bright (but with a good amount of bass), the neck is sweet and singing, a lovely sounding pickup.
I've never tried the Painkillers, but I know the PK neck pickup is ceramic so it probably doesn't sound particularly sweet.