I love Dimarzios but none of those 3 pickups are gonna get you as tight and close as you want for those bands listed. If you want to go with Dimarzio, get Steve's Special instead but I've had better luck with Duncans for most of those tones as they have a bit brighter presence....specifially the Duncan Distortion or Custom. But yeah, I would agree that the Custom would be best for trying to find the common ground in all those tones.
The Tone Zone will do early Dream Theater no doubts there but i do agree the others in saying that a Duncan Custom would cover the most ground and imo would be a good choice.
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the duncan custom has a quite dry tone that would lend itself very well to early 80's thrash metal such as metallica,slayer and megadeath. :burnout: