How about Blackhawk Legacy X6-P? it come with a clicky switch, and it take aftermarket LED drop-in with the outer spring on.
http://www.youtube.com/watch?v=bYY4xYqdKFg
(Beware the polymer one if you want to run high output drop-in, they seem to share the same model name.)
5.11 tactical had offer same holster with 3 different size, I was wondering they can fit the bigger head light like BC25, XT11...etc.
See Rule #3 Do not Hot Link images - Norm
I read some where the problem is caused by the RediLast battery's button top too big, and had make contact to the TK15 's reverse polarity protection. I guess you just need to stick some plastic sticker around the (+) spring of the bezel(the black color area) to disable it.
Hope this help.