The Glock 26/17 magazines are interchangeable. I carry a Glock 26 daily, and carry a G17 magazine as a reload. Giving me 10+1 and 17 easily. I also have a full size M&P as well.
If you can try the M&P compact, that is a great choice as well. There about a million options for this question, but I agree with the other helpers, that you should stick with 9mm, and probably go down in frame size.
Also, try this link:
Genitron handgun Selector
This might give you a few ideas. Make the search as general or detailed as you want!
Enjoy!