I also own a walther PPKS .380. But my normal carry is a 9mm XDM with a UTG double snap IWB holster that keeps it snug against my waist even under a tee shirt. 19 rd mag and I love it.
I carried the baby Browning. This is chambered in 25 auto. I find to be a very reliable done. The 25 auto is centerfire. Check these out online. They are sometimes hard to find. I have found that mine is very easy to disassemble and to clean. Parts seem to be made very well.
In a related "What do you carry ?" thread, I was thoroughly castigated when I stated that I did not "top off" the magazine, after chambering a 45 round in my Wilson 1911. The preceding 30 pages of responses seem to indicate that the majority of INGO members are comfortable with less firepower, and rightly so. Those who critisize others choices, apparently have convinced themselves that they will be attacked at any moment. The choice to go armed is a personal one; critics should stand down.
I used to carry as beretta bobcat 25 acp. It was my very first gun. I wouldn't swear by it, but 1 shot is enough to deter anyone and 3 or 4 shots is enough to get the job done.
I would carry a 380 as a backup if I owned one, but I will not go below a 380. Now that they are making the 9mm about as small as a 380 I will probably never buy a 380.