I have to disagree with the choice of the S&W Shield 9MM. I am old and have arthritis in my dominant hand. I had one. It may conceal well but for me there were other issues. The slide was very difficult to rack. The magazine was almost impossible to properly seat into the gun when topped off and the slide closed. It was also difficult to get the last round inserted into the magazine. I moved that one on. YMMV
The S&W Shield 380 EZ on the other hand is great. Recently picked up the non-safety version. I love it. A few more rounds through it and it will make its way into my carry rotation.