I can’t help you out with a preamp (I’m a passive kinda guy) but I can recommend a doozie of a humbucker. There’s really not much technology involved in pickups so the difference between a big-name pickup and a no-name pickup is often only the name… and about 150 bucks.
My recommendation is the MGB BK2000. It’s a quad rail… two humbuckers wired in series.
It’ll be the best $20 you’ve ever spent on gear provided you do two things. First, to tame the treble and feedback, wax pot it. Secondly install a series/split/parallel switch. Series will be the full power 18k, muddier, easily overdriven sound. Split will be a single 9k humbucker, not a huge difference in tone from series but less output, possibly good for metal for going from overdrive to a cleaner sound. Parallel (4.5k ohms) is where the magic happens in my opinion. This is the lowest output (but that’s what volume knobs are for) but the tone is articulate, well balanced (not muddy, not harsh highs) giving you a good spot in a mix and the strings become much more touch sensitive… meaning easy to change your tone by the way you play.
The volume is a push pull which creates a scoop to enhance slapping, but the EQ works in conjunction with the slap switch so you have control. And there are switches on the EQ board you can set to adjust the scoop frequencies. I really like this EQ. Designed for a Music Man but can be used elsewhere too
I tried an Ibanez with Nordstrand pickups over the weekend. They sounded incredible. I was really impressed.
Rio Grande Pickups can do series/parallel/split. They’re a custom shop and I’m not sure if they have a soapbar version. A lot more expensive than the ones @Korrigan recommended. Like $160 a pickup.
I’m like the Aguilar dcb and obp3 combo. I used obp3 before and like the wiring options as well as performance.
I have a set of Nordstrand big blade and their preamp on my Chapman, it’s passive with big sound. I think it’s warm and wooly options not clean and clear.
I always want to get the Fishman on my Spector but never got around it, every time I wat to pull the trigger I would consider get a quad(twin dual coil) Delano Xtender. It’s a little more work but it would pretty cool.
I’d say trust your instincts and go with Seymour Duncan, their humbucker are pretty cool. I think the Lemmy Kilmister signature serie is exactly what you are looking for, plus they have the Thunderbird bass pickup set. If I’m building a thunderbird, I’d definitely get something like that.
As for preamp, I used the Steve Bailey artist set on my first Fretless jazz bass and it was really easy and useful control.
Splitting humbucker coils definitely does. But series/parallel is just the way you solder the normal pups to the other electronics. And it’s simple to wire them to a switch that flips from series to parallel. Standard wiring is parallel.
My main bass for years (and still happily on the bass rack, just not as in demand) was a Modulus Sweet Spot.
It’s a '95, and it has a giant EMG soapbar towards the bridge - at about Ernie Ball position.
I love it… for massive volume, huge output, and metal/high-fidelity rocking.
It doesn’t like the mids, and thinks that mids are weak, and have no business being in a pickup, or a band mix, and, it goes on to say, “if you wanted mids, why didn’t you go buy some pitiful 34” scale 4 string toothpick to go get jazzy with?"
So…
It’s great, but only for certain things.
Luckily for me, it worked out… and I went out and bought a few 34" scale 4 string toothpicks to get jazzy with.
