Re: Which Pickup for....
The JB in general is a good pickup, but I doubt it will be the best choice for what you describe. Jbs tend to have a looser bass and a high mid spike. Not my first choice for extended scale downtuning. Mahogany is generally the tonewood not to use with a JB as well, just as a generalization.
It is passive, which is pretty much the only criteria you posed that I would really give it a thumbs up for. It can be somewhat aggressive, but nowhere near as aggressive as some things. If you want the sound of a JB in metal, think Megadeth, as that was Mustaine's pickup choice for years. However, the JB tends to sound more aggressive to me in alder or ash than mahogany. I would say it suffers a bit in drop d. I tried it in B standard in a baritone once. Would not recommend. It just is not where I thought that pickup excelled.
But seriously, a Black winter is exactly the pickup you described. It is versatile, but it might be the most aggressive of the duncan line. It also has IMO the best string separation of the humbuckers, and the best clarity.
I only have a Nazgul 7 and it reminds me of the BWs little brother. lower output, but sharing a lot of characteristics.
