For Kydex, leatherface, rainwalker, Dave Brown (Buy Brown) or Okuden are all possible choices. Semper Paratus is the only maker I'm aware of that does Nylon. The first two hang around the Scrapyard (Dave Brown occasionally), Dave Brown hangs around the Busse forum on BF regularly and Okuden/Semper Paratus contact info is on the Busse Combat site.