Re: Pickups for Ibanez J.Custom - for instrumental rock
I'm surprised noone mentioned the Black Winter yet. That pickup is highly underestimated IMHO. It's got the warmth, the fattness and power to give you fluid leads but it never gets brittle in the top end or saggy in the bottom. It's not really midscooped but fairly even across the spectrum. For rhythm it's also great. I find it a shame that it's marketed towards black metal and the likes. It's like a happy marriage between the Sh6 Distortion and the Invader: a bit of the grind and cut of the distortion, a bit of the fatty girth of the Invader, but a unique beast all of its own.
For the neck: I'm very partial towards the jazz Bridge pickup in the neck nowadays.
*The sentient is a bit too scooped, too clean and jangly for allround purposes.
*The standard Jazz Neck is that but even worse; the Fullshred Neck is that, but even WORSE. They are great options for other purposes, but if you want one allround neck pickup that allows you for lead tones with a fairly substantial midrange, bottom end and power, the Jazz Bridge is the way to go (unless you wanna go hybrid).
*The Screaming Demon is IMHO way, way too fat in the neck position, to be honest.
*I have zero experience with the Black Winter neck pickup.
As for the other popular choices:
*the 59N is a decent neck pickup but not one of my favorites (great in many hybrid-recipes but not on its own, imho).
*The 59B is also a great choice but can be a bit boomy with a bit of sag in the bottom end.
*The Seth Lovers (bridge and neck) are amazing but not powerful enough for the needs laid down in this topic.
*The Alnico2Pro has never been my favorite: I compare the a2pro vs Jazz to a ribeye vs sirloin/newyork strip steak. The a2pro has too much fat all across the spectrum (like a ribeye) and the Jazz has just enough of a fatty edge to give you a bold, powerful feel but not enough to get in the way of cutting through the mix.
As for Dimarzio: no suggestions. Only negative opinions

(don't like Dimarzio; never cared much for its tonal palette across its lineup, sorry).