Look around at what the other shooters are using at your next match. Around here Kydex is the predominant holster material. Yes it will wear the finish, but so will leather. I have read about a lined Kydex holster, but forget who makes that holster. I use the Blade-Tech OWB model. Comp-Tac and ready tactical are also very popular models.
Not USPSA, but here is a link to the IDPA magazine, Tactical Journal. (Very slow to load - save it to your computer to save time) This edition lists all of the equipment used by the participants at the 2012 nationals. Blade-Tech and Comp-Tac made up approximately 90% of the holsters used at the match.
http://www.idpa.com/content/tactical...al/12V16I4.pdf