Both Mr Cesna and Mr Piper make their airplanes in the USA. The jacks are absolutely standard. I have found that sometimes when I am using my David Clark headsets and I fly with somebody else using another make (usally super cheapo's), there is a compatability issue resulting in their headsets not working at all.
I've flown a few different types of light general aviation aircraft now and found all of the jacks standard. I did note that the passenger jets seem to have different jacks as do the military but since I fly neither, have found no problems to date.