I bought GraphTechs for my Jazzmaster... direct replacement. I think I called them directly... not sure? But they do make them and they're a world of a difference. I used to break strings all the time on my JM... now I can't remember the last time I broke one!
Call their 1-800 number, they're more than helpful in getting you the right saddles. They'll even tell you not to buy directly from them, buy from someone else like Stewmac, it's a lot less expensive.