Buy the Glock in 40 S&W then use a replacement bareel to go down to 9mm if the 40 is too much for you. I have done this and am very satisfied. I went with the smaller Glock for carry and put a Wolfe barrel in it to convert to 0mm. You can use the 40 mags, too. Just carefully pinch the feed to the 9mm separation.
An air gun?