There are several here who can make custom caps including Jim baxter, and Dave Albrecht (nbll01), but you could also call Ed Himself as I think he uses a custom pin (312) 519-2505.
That's vague -- do you want custom JPs on your EY, EY made EY caps, or just regular ones? The regular ones you can buy anywhere, there are custom JP makers on this forum, and the EY ones...you gotta ask Ed to do that and they don't come cheap because I believe they're made to order.