After viewing a lot of the footage specifically featuring "Chibs" with his blades and rig, I'd have to say that it's a modified jack ass rig with custom sheaths. The blades themselves, I really don't have a clue as even freeze frame doesn't give enough detail to really get a good look at them.
Also, I've only seen two K-Bars in the show, as a majority of them seem to be various Cold Steel knives. Trig carries a Cold Steel, as did Juice, and a several others. That's about all I can add.