The 950 is only still available in 25 acp, and is a single action auto. That being said, I think it's the best 25 acp there is. 9 shots, and extremely reliable,
I also had one in 22 short, and it was fun if not really powerful.
The 21 a is available in both 22lr and 25 acp, and is double action /single action auto. It is my favorite 22lr pocket pistol (never had a Walther TPH) and is quite accurate and reliable with proper ammunition.
Either would serve well as a pocket gun.