I think Allparts and Warmoth both offer Jaguar/Jazzmaster bridges and saddles. I'm happy with Mustang saddles, myself, though I got pretty good performance out of the old stock saddles as well. Proper Jaguar saddles should come with three different thread-groove sizes. I don't know weather the above-mentioned saddles are vintage-correct in this way, or not.
If you get Mustang-type saddles, get the saddles (or the whole bridge) from Allparts, since their saddles, unlike those from Warmoth, are wide enough to touch each other when the guitar is strung, making a more solid contact with things for stronger tone.
Also, there's someone out there making titanium saddles for Jaguars, Jazzmasters, and Mustangs, that are supposed to be available through Allparts, as well.
