When I last purchased Stellite 6K, it was directly from Stellite Corp. Spent a few thousand $'s and they treated me very well...even wanted to make it to the thickness I desired. It has a black, almost like scale finish that needs to be removed.
I believe that Alpha Knife Supply is the exclusive source for Tallonite iin the U.S. The Bybees are fine folks to work with and very responsive to your needs. Talonite has a nice shiney finish
As you have probably found, neither material is inexpensive and you will go through more belts with them than with steel.
There is a fellow in Kokomo, IN, Roger Young who makes multiblade slipjoints with this stuff...I believe he uses Stellite, and then file works his knives.....