You mentioned your desire to have this next gun for increased HD or CCW options.
For CCW, I like small easy to carry guns. I could see a Kahr P9 or P40 being easier to carry without giving anything up. If you went wheel gun, a S&W 13 3" or S&W 640-1 would both give you 357 power in a small handy package...640 being smaller by quite a bit.
For HD, your PPQ looks like a good choice. A rail light would be a good option. ... Or to get a new gun, a Glock 17 with a light and plus two floor plates gives you lots of weapon for HD when you will likely have only enough time to get something in hand and go. A mag and searchlight in the left hand and G17 with a weaponlight is a lot of horsepower without requiring "suiting up".
Last, a second caliber might be nice for when the LGS is out of your caliber as we have seen lately.