Ksail, get the AR 1st, but after that, I have a multitude of 9mm's, including CZ and Glock, I love my CZ75, it is an older military model without import marks brought in through Germany by a GI, it shoots good, and is completely reliable. The thumb safety is a reach for me, when cocked and locked, may not be for you, but try it. The main thing these days are extra mags, and what you are willing to pay for them. Since you already have a model 19 Glock, I would steer you to the model 17, or 34, and I can describe to you a simple modification to the frame where you can still use the 19 mags in a larger frame Glock.
Go ahead and find out what new CZ mags cost and the availability, being on the long list, they might not have increased that much yet, and still be readily available, I would buy 10, if you go that way. But if extra mags are 30 bucks or more, I would stick with the genre you have chosen. Glock. My CZ likes hot ammo, 124 grn carbine ammo, prints very well.