if you're thinking about getting a G42 as a CCW, you really ought to consider a quality single-stack 9mm instead.
Id just go with the 26. No need to short yourself.
I have a couple of 42s, and they have been good, reliable and accurate guns so far. As much as I like them though, they really arent all that much different in size compared to the 26, and I just dont want to give up what they have to offer.
I also currently have a SIG P230, and an LCP. They have been about like the 42, especially the P230. It will allow you to stretch the distances a bit further than the smaller guns, as it has decent sights. The 42 shoots just like its big brothers, and at about the same distances.
I had a P238 when they first came out, but they were pretty rough back then, and not at all reliable. They were "soft" shooting like the 42's, and accurate, when you could get them to shoot.
Personally, "pocket" wise, I still feel the Seecamps are the one to beat, if you need a "little" gun. Mine are in 32, and I really dont see the need to go up to the 380 version. For what they are, there really isnt that much difference in performance between the rounds, and the 32s are much more comfortable to shoot.