P239 for carry
Hello fordson,
My first thought is that you consider having a qualified instructor or friend evaluate your technique to see if they could make some suggestions that might improve your ability to control the "snappiness" of the .40 caliber Kahr. If that works, I could then consider changing out the sights to something that works better for me.
If that doesn't do it, I would strongly consider moving to a 9mm caliber alternative. Besides it being overall less "snappy" than .40, you've got so many readily available choices in 9mm SD ammo, you could really start to fine tune what works best for you.
And as much as I really really like Sigs, I agree with Arik that there are many other choices these days that might be better options for IWB or other methods of deep concealment.
I really do think the P239 is a bit of a "tweener" in that regard. If I was bent on carrying a nearly 30 ounce Sig pistol, I would personally choose a P229 that weighs about the same as the 239, is just a tad thicker, and increases the 9mm mag capacity from 8 to 15.
I would also strongly consider an XDs in 9mm to see how their standard hi viz front sight worked for my eyes. I could choose flush fit mags or the higher capacity extended mags depending on my method of dress and concealment, IWB or OWB.
Best of luck. Sounds like a fun project to me.