Ruger SP101 is one of my all time favorite revolvers. But let me maybe use a different tact. If you think you're going to need more than 6 shots in a defense situation, especially one in a urban social setting, you don't need to use speed clips, you need to get the hell out of there as fast as you possibly can. That is good advice if you carry a weapon with 6 shots or 16.

Trust me, I'm not some Dove or anti CCW or personal protection. Far from, but you don't ever want to be in a situation where you're in a firefight and have to reload. The faster you can get yourself out of the situation the better. A concealed firearm puts you a leg up on the general public for personal protection but a CCW is not a hero license. I don't mean that in the sense that I am insulting you, but whether you have the protection or not, you're best bet is to always try to get away fast.

And if I totally misread your intentions or situational need, I apologize.