If you insist on a .45, I like the 220, however I don't like the .45 in the first place.
I've done some high speed photography on a 1911 cycling, and the reality is that the case is so squat and short that it has difficulty ejecting. When you hold it by the rim, and pop it with an ejector, it tends to want to spin in place, rather than being projected to the side. In the 1911, the case will actually spin a little over 90 degrees in. the chamber, then bounce off the leading edge of the ejection port before clearing the gun. One wrong bounce, and you stovepipe.
I have not done similar photography on a 220, but assume that SIG added some improvements to a 100+ year old design.
If you do want the highest relaibility, I'd recommend a hammerless revolver. Revolvers don't typically jam, and you want the hammerless so it does not snag on your clothes.
In a defensive scenario, I don't believe you need a big ammunition supply. A 6-shooter will convince a guy he really did not want your wallet baly enough to let you take 5 more shots at him.
Art