I don't know Snow, but the rest, with the possible exception of Yost, are "Production/Custom" shops. I don't think you can get a ground up custom, built by the man in charge, from any of them. That's not saying that they aren't darn fine pistolsmiths, but their business models have changed.
My vote goes, in no particular order, to Steve Nastoff (I had heard that he was building some guns again, but I haven't been able to verify it) Paul Liebenberg, C.T Brian, and John Harrison. If you haven't seen John's work, he has an almost cult-like following in Georgia. Exceptional work, and a true Southern Gentleman.
Scott