My own preference is to DiMarzio pickups, but I've heard good things about Seymour Duncan as well.

Something to bear in mind is the way the pickups are wired when they are installed. I suggest you stay away from setups that simply short out one of the humbucker coils to get a single-coil sound.

If the coils are connected in parallel, you keep the hum-rejection ability of the pickup while getting a nice, clear, sound. Series connection of the coils will produce the full, chunky, 'humbucker' sound. Stewmac, and others, sell control pots with push-pull switches built into them, so you don't have to make additional holes in your guitar body to install series/parallel coil switches.