Welcome to the forum and it looks like you've been doing your homework.
A few comments:
PPK/S- I have one and it has never failed in any manner, so far total reliability. IMHO the .380 is a marginal defense cartridge, though an appropriate caliber for a BUG/pocket pistol; and shot placement is always important regardless of caliber. My PPK is a nice gun, it is pretty thin, but it is pretty heavy for its size. I rarely CC mine, there are better choices out there. Right now I CC a G-27 or 1911, and sometimes my LCP, it just depends? I'd suggest you take a close look at Walther PPS, they are
thin and come in 9mm or .40. Some may say they are a bit ugly, but I'm willing to buy one and carry it.
Sig P239- I think they are great CCW and I intend to get one in DAK SAS, I just haven't decided on 9 mm or .40? At least I'm using that excuse to delay parting with my $$$.
S&W 642- As you already know a great CCW revolver.
1911's- There are a lot of great one's to choose from and typically a favored choice by lot's of folks for a CCW. Personally I have a Colt Defender and it has functioned perfectly. If you choose a 1911, you'll need to thoroughly train and practice so you'll function instinctively with this platform. It is a big caliber, and as the saying goes no one has ever wished for a smaller gun during a gunfight.
I think that you have made some good choices, but you're at the point where it typically becomes a personal decision.