The XD Subcompact is at the top of many people's lists of late. It is an excellent choice, in either 9mm or 40. Super-reliable, concealable, and with the 16-shot long mag, is a joy at the range. I own 2 XDs.
Shot-shells? No. I've never heard of a shot-shell for semi-autos. I'd guess too many issues with feeding and ejection with the abnormal case mouth, and most rimless autos actually seat in the chamber on the lip of the case.
Stick with a wheel gun for snakes, or jus shoot 'em at a greater distance... with a 9mm. THAT'S accuracy.