I was looking at maybe getting a quickdraw sheath for a folder.

I've seen the Merlin from CRKT as well as custom one I found on bladeforums. http://www.mnsi.net/~nbtnoel/speeddialers.htm

Are there any others? I want one i could use with a merc harness and preferable with different types of knives.

Any of you ever use these kind of rigs?