I’m saving up for one of these right now....never used them, but have read great reviews.
Comp-Tac
http://67.52.203.44/
Also, I have used a Clip-Draw with my Glock 27, along with a Saf-T-Blok to block the trigger while carried IWB. This offers a few different carry options, as well as the option to carry in cold weather or hot weather clothing.