bridge/neck - 81/85 ala zakk wylde, 81/81 ala kirk hammett, jeff hanneman, 81/60 ala james hetfield. personally, i like the 85 in the bridge. fuller with more lows and less shrill than the 81. for the neck i prefer the sa. less woofy than humbuckers. if you have to go the hummer way, the 60 is a good choice.
i had a 85/sa/85 setup before...its was great for all kinds of metal... if you dont want the active electronics route...you can always got for dimarzio or seymoure duncan pickups....
at the end of the day i would say it is your AMP or dist unit that will give you the desired metal chug you need.
ive been playing some metal stuff at home with my bridge single coil and it works fine.