I recently bought an ESP LTD EC256. The guitar feels good, plays good, looks good, I just don't care for the pickups.

I'd like to stick with passive PUPs. The guitar will be used for C standard tuning metal. Budget is $200 for a set, tops. Preferably a little less.

Looking hard at the Seymour Duncan Nazgul/Sentient set right now.

Get the Seymour Duncan SH-5 Custom. That is the most evil pickup ever, Satan will literally come out of your closet just by playing one chord. Listen to Necrophagia's "Dead Skin Slave", that is a very good idea of what the Custom sounds like. I'll post it down below

Baby Joel's rabbit profile picture is kinda cute. #TeamJOEL
Oh and Necrophagia plays in C Standard so there you go.
Baby Joel's rabbit profile picture is kinda cute. #TeamJOEL
Nazgul/Sentient or Black Winters would be my choice. Both remain tight tuned that low. Check out the soundclips and videos out there, but you really can't go wrong with either.