Two thoughts....The saying...probley don't have it 100% correct, goes something like this: Beware of the man that only has one gun, hes probley pretty DARN good with it.
I had a report on stopping power of different calibers and don't remember if I posted it here, but of all the popular ones two were tied for kills, .22 and .357. All took less than two shots to stop the aggressor. So if you can put 6/8/9 with a .22 in the correct spot (same goes for ANY CALIBER) it will surfice.
And Im with him 100% on the revolver vs auto, been there, done that.