I think I would rather use one pistol at a time. I don't think I would shoot two pistols very accurately and my luck, within seconds of pulling out two pistols, I would see something I needed to pick up.
The XD-M 9mm holds 19 in the mag. I have heard the FNP 45 holds 14 in the mag, but I don't know much about those pistols except they are large. I would likely include my Glock 22 in the mix as 40 has good penetration while retaining some size.
As for rifles, I find it relatively easy to either wear a pistol or keep one close by. I might have a rifle and mags in the safe or a closet, but not generally close by. Even if you were in a SHTF scenario, on Day 4 when you are thinking about what you can afford to eat that day, you may not be keeping your rifle with you. I think if things are to the point that National Guard or Police are patrolling heavy enough to give problems, the SHTF scenario is likely over or near it.
