It's difficult to do what you want with one gun.
Kahr says 200 Round Break-in. It's true and perhaps then some if yours ever has to go back. If they replace parts you can sort of have to start over. Kahr also recommends slide release as opposed to SS. I like mine but they can be a challenge. They seem to go one way or another. Trouble free or not without challenges. The new ones supposedly have an improved trigger.
In my view pocket carry comes down to weight. I simply cannot deal with anything in my pocket over 15 ounces loaded......
If I were starting over today...I was where you are 7 years ago...I would likely do the following combo. LCP, Kahr 9 or LCP S&W J Frame.
As it turned out for me with what was available at the time I did Seecamp .380 (that would be the expensive LCP today), Kahr PM9 (too big and heavy for the pocket IMO) tried a 642 snub, too heavy, liked the format, went MP 340 with CT Grips.
To summarize then LCP, and light snub, Ruger or Smith.
Also I don't recall seeing the Walther PPS as a possible. Wouldn't work for me, but might for you.
In the budget price range don't over look the BERSA.
By my criteria by weight the Diamondback DB9 would be the only one to make the cut...and I know nothing about it.
I still own all these.
In pictorial summary I pocket carry one of these two-
Neither is a 9mm. But one is capable of .357 Magnum.