There are actually lots of very good after-market pickups currently availabe on the market for a jazz bass ... Fralin is surely amongst the best; the same may be said, in my opinion, of the pickups from Lollar, Aguilar, Nordstrand and Klein.
It would be worth mentioning the Fender PV '64 pickups, which are killer 60's jazz bass pickups and could be found at a lesser price than those mentioned above .. I personally believe that they can incarnate the epitome of the 60's jazz bass pickup fairly easily although Lollar's and Klein's pickups may be considered slightly clearer (at least for me, but this is subjective anyway) ... in terms of true vintage tone, I (always personally) deem Fralin's standard pickups being half a step below Lollar's and Klein's pickups as, I believe, they tend to sound a little brittle in the high register, more than what the Lollar's and Klein's seem to do (it seems that there is a sort of cult for the Aero pickups, however I don't consider them any better than those which I mentioned .... to be honest, I don't like how they sound, hence I didn't talk about them) ... however, when we consider the personal taste of each bass player all of the above considerations fall ... everyone should save enough money to test and finally adopt the set of pickups which better aligns with his or her personal ideas about how a set of passive jazz bass pickups should sound ...