I can have a headstamp die or other stamping die made to spec. It isn't cheap, but I gather you aren't looking for a cheap solution. As Toby pointed out, any plating would have to be done after stamping (and polishing).

A friend owns a mid-sized fabrication biz which has many punch presses and pressbrakes. For entertainment, he's been making stamped coins and conchas for horse clubs that he rides with. He has the die made by a company he deals with in his biz. Pretty impressive (pun) stuff.