Theis Holster builds a very nice Hybrid IWB holster, and their website does lits the Walther PPQ. $65 including shipping. They say a 2-3 week delivery, but I got mine in 8 days! http://theisholsters.com/holsters.php
I have one for my KAHR CM9 which I have been using for a couple weeks, and it has proven to be comfortable, and concealable. Very happy with it.