Have a quick glance at these links:
There are other links as well if you care to google this incident. It has been highly analyzed over the years. IMHO it is important to learn lessons from the past, particularly when they have been so dearly paid for.
I disparage no one who participated, but merely note that a highly trained FBI Agent with SWAT experience emptied a S&W Chiefs Special during an intense gun battle, was not able to reload that revolver quickly under attack, and was subsequently KIA.
If I were faced with your dilemma, I'd look at which of those two choices you can reload more rapidly. I suspect you'll find the LCP is easier and faster to reload with a spare magazine than the revolver, however, your mileage may vary.
Just one guys opinion...but whichever option you select, there is a remote possiblity that you may need to reload it under fire.