Production, off the shelf leather: Galco or Don Hume
Handmade: RafterS. I liked the holster they made for my GP100 enough to buy a holster and matching belt for my Kahr K9. The best part? The combo wasn't any more expensive than production leather, even after upgrading to Sharkskin.
I'd be happy with Galco or DH, but most of the time, the belt loops are too large. I wear a 1.5" belt and they like 1.75" loops that are extra wide as well. Once I lose a little more weight, I want to try a Milt Sparks Watch Six or Comp-Tac CTAC for my K9.
BTW, how comfortable is kydex for IWB?
Chris