Re: Which hums for a ash body jaguar
A2 pickups tend to help with the mids and mellow out the brightness a bit, but may worsen the problems with the lows. Or may fix it. Very hard to predict exactly how they'll mesh, especially in an unfamiliar design.
If you like early David Lee Roth-era Van Halen, the '78 or (for later stuff) Custom Custom/Fender pickups may work for you.
Is the '59b in the neck too thick, lacking in mids, too loose, or all of the above?
The Jazz Chorus can be tricky to make work with humbuckers, I've known people to use pretty bright setups into them and get some pretty interesting sounds, but it's pretty unforgiving to harsh pickups.
Funkfingers' suggestion of a TVJones FilterTron might be a good choice, good combination of twang & jangle without hum.
P-90s might also be a good choice.