It's easy to build and maintain proficiency with two handguns. If you're willing to put in the time, two works great. The PPQ is a great HD, duty, and range weapon. It can be carried IWB, in the right system. If you're planning to do that, be prepared to get a quality holster (Crossbreed Super Tuck, etc), and a gun belt. That set up goes a very long way.
I prefer to have a deep conceal option, as well. The SR9c covers that nicely. As far as the trigger goes, I love it. Specifically, the presence of the thumb safety allows me to love the lack of take up, and smooth pull of the SR9c. That pistol is a very combat capable platform. The trigger makes it easy to shoot with speed and accuracy.
That's my .02