I'm not sure I would make my first gun a small mousegun. If you want to keep the size down, I would opt for something like the Keltec PF9 (which I own) or maybe a Taurus 709. The Keltec is thinner, and has a rail......and is very concealable. In fact, it's the thinnest 9mm you'll ever buy. It's not exactly a range gun, but more so than the 3 you mentioned.
If you are going to buy one of the 3, just pick up each one and decide which one is best for you. I own the Ruger LCP and am very satisfied with it. However, only the Taurus locks the slide back on the last shot. The other two do not. Not sure if this is important to you, but it's there.
