It's a pain in the arse to order from Kow Hoo at a distance: I got them to make me a pair like this once, but they were very reluctant to do so. The last-maker is ancient, but he's very good indeed, and the shoe will fit perfectly. The quality is good, but not excellent (think Crockett and Jones). I've not seen Vass shoes in person, but I have no doubt that they are superior.
Edit: On the plus side, they will do any design you specify.