I really like the Duncan Custom (Sh-5) in the neck I feel that it's pretty similar to the JB, but with a slightly bigger, better defined low end with a tad more bite and clarity.
Duncan Custom, Duncan Distortion; in bridge. Duncan Jazz, Duncan JB; in neck. I feel the Emg 81 is a good pickup, I used to use them religiously, however, passives are the way to go if you want tone.
it's all subjective man, that's why i say buy a shyteload of guitars and have every combo possible.....forget your house payments
I have almost every Pickup you have mentioned
on different guitars, and I have to say that :
1 - the Dimebucker has got a very tasty chunk and round
sound, but also very bright, I like it both for rhythm and leads
2 - the JB have a good balanced rock / metal sound, it was a standard
until a few years ago, now the more powerful and extreme ones
are being more used of this one because of the low tunings and super higain
needs modern metal has
3 - the emg 81 are just a standard in metal. No noise, hi output,
someone says it's not good for cleans, but cleans in metal are never "really" cleans, someone calls that the "sexy clean".
4 - duncan distortion - this one is the last arrived in my family, and is the one that shocked me. An amazing power and hi output for being a passive pickup, even used in guitar rig or other vsts it pushes out
a very strong sound, and very suitable with low tunings.
but the very choice is not in what the pickups offer, but what are your needs!
what are you going to play?
rock, metal, blues, death, brutal???
If you get that new Seymour Duncan Liberator thing that lets you change pickups with only a screwdriver, no problem!
However, for a guitar like the Xyphos, I would have to recommend the EMGs also. I don't have any experience with them, but Piotr from Vader, a pretty much unknown Polish death metal band is using a custom RAN guitar with identical specs to the XPT700, and the tone sounds pretty good to me.
The other thing you might want to consider are the Duncan Blackouts. Again, no experience, but my teacher told me that chasing after the tone from an album is just stupid because a lot of it is multiple tracking and other studio tricks that make the guitars sound HUGE. So its better to look at reviews and those kind of things to try and nail down some solid equipment with a good reputation.
a q-tuner in the bridge will be your best friend. i just order a set of q-tuners for this 7-string super strat that i'm building.
Those things seem pretty versatile, a lot of different adjustments you can make with the individual poles and crap, right? I'm thinking of getting a pair in my new bass, when I get the cash to have it built.