Title basically says it... I’m interested in the series/parallel thing for jazz bass (I want to be able to get a more p-like sound if I want) but I’m wondering if that would still work with J pickups that are hum cancelling already. (specifically looking at the SD hot stack). I would also like to be able to rewire with VBT setup instead of VVT. Is it possible to have all of these things? Would the series tone be different from other j basses with the same mod because of the pickups?
 
The series mod and V/B/T will both work just fine with humbuckers. The tone will likely be different than other Jazz basses, unless they have the same electronics package, but the humbuckers won't have anything to do with it. Putting the pickups in parallel will still thicken your mids, just like single coils.
 
rewire with VBT setup instead of VVT. Is it possible to have all of these things?

No, it's not possible to have a balance control & inter-pickup series/parallel.


Would the series tone be different from other j basses with the same mod because of the pickups?

Yes, because you're working with four coils, not two. The phantom coils are only supposed to be there to hum-cancel, but they definitely shade the timbre.
Series/Parallel would actually work better with a set of pickups where one pickup is reverse-wound, reverse-polarity from the other.
In that way, when they're both on full volume, they hum-cancel.

I'm not sure that if you disengage the phantom coils if the remaining coils are a hum-canceling set, but I doubt it.