Sig makes some of the most rugged and reliable handguns out there, so you certainly won't go wrong w/a 239. However, I personally feel that a 239 is an expensive and bulky way to carry an eight round mag.. A Glock 26 will be slightly smaller, weight a lot less, cost a lot less, be just as reliable, and carry two more rounds. Of course, personal issues such as grip angle will play a big role in one's choice.
I have a Kahr as well, and I like it a lot. Makes a great CCW. Be aware though that the poly Kahrs can be problematic, which is something that you will not likely have to put up with if you buy a Sig/Glock/HK/Walther/Springfied/S&W. The all-metal Kahrs do seem to have a much better reliability record, and the one that I used (an MK9 belonging to a friend) is a 100% performer with an unbelievably good trigger.
The PPS has yet to establish a track record, but the P99 Compact is a very good choice to consider. It would however be a bit more expensive and likely harder to find locally than a Glock.
An S&W M&P compact might be worth looking at, as there is a promotion that has a $50 rebate and two extra magazines.