Id look at this web page as a reference for how the hat should look and then start looking at the current hat makers. (Stetson, etc.) Other than that...I know that some have had less than optimal experiences with Dirty Billy's and it appears that the F. Burgess folks website is no longer up like it used to be. But for custom hats, these would be where I'd start looking.
F. Burgess & Co.
200 Pine Place
Red Bank, New Jersey, 07701
(732) 576 1624
or
Dirty Billy's Hats
Hope this helps...Good Luck!