This is getting more and more difficult.
The Bersa is about perfect, but bigger than it should be. I originally thought it was the same size as the PPK, but it turns out it's significantly larger.
The Polish P-64 looks really cool, about the size of a PPK but a bit more powerful and 1/3 the price. Put the more I research them, it looks like they have an older design that doesn't have adequate safety mechanisms to protect against accidental discharge from either dropping, or from the hammer catching and falling. I just don't think I'd be comfortable with it.
So while I'm on the subject of the PPK, let's talk about it. Everything I read about it says it is finicky at best, and downright unreliable at worst. Even the people who love and praise them say things like "It's a great gun, precision made, blah blah blah..." but eventually get around to their little disclaimer like "and mostly reliable if I only use (Exotic Brand X) ammunition". Or, "It only stovepipes about once per box." Like that's OK. One guy actually defended it by saying that his was 100% reliable if he thoroughly cleaned it after every two mags he shot through it, claiming that was all anyone ever needed to use it for anyway. Can you imagine if some inexpensive brand did this, like a Kel-Tec or Bersa? These same people would be trashing it. So, no thanks on the PPK. No wonder James Bond wanted to hang on to his crappy Beretta .25.
The Smith CS9 seems to be almost the Holy Grail. Small, 9mm, metal, safe, same action as my Beretta, decent looking. But, they are scarce, and a bit on the big side. If I find one at a decent price, I am going to get it to try for a while at least. But I'm a little spoiled by the tiny size of the PPK and others in that range, so we'll see.