Hi
If you want a Kepi, I think it's Dirty Billy or possibly Quartermasters Shop. I remember reading that while most Quartermaster Shop stuff is good, their Kepi's not so much. I doubt I could find where I read that since I didn't want a Kepi then anyway. Starbuck's stuff looks good, but I haven't dealt with him.
If you want a period slouch hat, then pretty much any custom hatter can make a great one that fits your head for between $250 (Bunny fur) and $600 (100% Beaver). As long as know a crown height and a brim size you're golden. I can recommend Mike Moore of Buckaroo Hatter in Covington Tennessee, and Roy Jackson of Jaxonbilt Hats in Salmon Idaho. Roy sends you a conformer to measure your head. I sent Mike a copy of the outline Roy used... If you can get into a custom cowboy hat shop with a color, a crown height, a brim size, a ribbon width, and a bow style it's pretty much yours. Those are the TWO cowboy hat guys I've dealt with.
Later