Hi
The 1911 is by far the classic single stack 45 acp pistol. I would check it and the P220 out. Both are fine pistols. If you have a problem with both of them then finding something in 45 is going to be tough.
If the grip size is simply related to the size of your hand, I would very much recommend checking out the 40 cal S&W M&P with the small grip insert installed. I have seen it fit people who could not otherwise properly grip a centerfire pistol.
If the issue is concealment, then a thin grip 1911 is about the minimum you are going to find ...
Bob