If you are not averse to doing it your self, knifekits.com has taps, drill bits, clips,etc. for reasonable prices. I made one of the DDR 2's and mounted the clip for tip up carry. Works just fine, just be careful with the tap. I broke mine into several pieces because I didn't use enough lube(first time doing it). Practice on an old beater knife, or some scrap metal. Hope this helps.
Droopy