IF you were to ask me:
First off, if you've never played or spent time with any Alembic and your reference(s) are everything else, prepare yourself.
Regardless of AXY, MXY, or a full Series electronic package, I promise you you've never heard anything like what's coming.
I'd suggest AXY's with Signature Electronics if you still have time to make the choice of what you're having built in. AXY's are the more neutral alongside FatBoys which are a bit more toned like other pickups. Think the difference between excellent studio monitors and excellent home hi-fi speakers, that's the closest analogyI can make.
The Sig Electronics would be master volume, balancer, then a tone control and Q-switch for each pickup. This gives a LOT of variations, anywhere from a super bright 'clavinet on meth' to utter mumbling organ pedal tone, and everything in between. Include the blue box preamps internally to set your master blend.
Regardless, the best I can tell you is that there's not a single player anywhere in this forum who upon recieving their first Alembic didn't find the flaws in their technique that they simply never heard on any other bass, or heard big differences in one brand of string to the next. These things will make you a better player, and after close to 40 years playing bass, these were the ONLY axes that did this. Don't be surprised if suddenly your amps may seem lacking, either.
Good Luck, and All the Best,
JW