There is not a definitive answer to your question, but I'll give you my take on it. I keep at least three magazines for each carry gun. I like to have a second magazine with me. The third is for times when I go to competitions that requires two spares. None of my carry guns offer the flexibililty for having different sizes of magazines like yours so I don't have to pick between different sizes. In your case, try to conceal the gun with the different magazines and see how it goes. You will probably find one with smaller capacity is easier to hide.
For home use I have a 9mm with a 15 round magazine. I don't usually keep a second loaded magazine, but I probably need to start rethinking that after some of the home invasion stories I've read lately.
I know the above was not horribly helpful, but maybe it will give you some food for thought.