Wow...a SHTF scenario, and not one of the arms listed has a suppressor?
I see a lot of big BANGS, enough to do just about anything you'd want to be able to do. But if you want to keep being able to do that, you'll have to be able to do it a little "quieter" when need be.
I'd look into a couple cans, at least one for the .22 pistol or rifle, tends to not spook the rest of the game.
If need be, get one for the 9mm/40/45 whichever you decide. I also have one for the AR, and one for my bolt-gun. Even if they do still hear a sound, it is pretty much non-directional, so alot harder to figure out where I am.
I'd try to stay with the regular rounds, .22LR, .38 Spec., 9mm, (.40 might be pushing it), .45ACP. in the handguns. Sure, maybe splurge on one high-power handgun (.44mag/.454Casull/.460S&W/or .500S&W) as a "just-in-case" last resort piece. Never know when Yogi or BooBoo might get the drop on you.
For long-guns, again .22LR, 5.56/.223, 5.45x39, 7.62x39, .308/7.62x51, (maybe .44mag for a lever action - so you can double up on ammo for firearms), and a good long range round. Mine is a .338 Lapua Mag. Some may opt for something in .50 BMG. Your mileage may vary.
Shotguns - if you can keep one of each, why not? Don't know that I would go crazy with a Saiga 12, but to each his own. K-I-S-S works for all of these. Hence, I keep pump-actions in each .410/20ga/12ga. - with extra barrels to extend what you might want to use them for (slugs/buck/shot) My 20/12ga both have extra rifled barrels w/ scopes on them, 24"-26" barrels w/chokes, as well as short barrels for QCB, the 20/12ga both have Knoxx (Blackhawk) stocks, in the form of the Comp Stock for the 20Ga, and the Spec-Ops for the 12ga. If you've never tried one before, try it - you won't go back to stock. Pumps are either Remington 870 or Mossy 500/590.
For semi- work, I keep a Mossy 930 SPX, a Benelli (finicky at times though), Beretta 391, Winchester Super X2, and a Remington 1100. All have the extensions - if you need more, then feed it. No need to weigh it down with a 20rd mag - imho.
Anything larger - wait for the right time. Main reason I stick with these, other than the .338 (but even that is changing to be more common on the SHTF fields), most of what I have listed is going to be fairly common, and easy to pick up replacements for, in parts (whole guns) and ammo.
But then again....what am I saying? I lost all of my toys when we were re-enacting the Titanic. But...for what it's worth, that was my .02.
Oops, forgot a few essentials -
last but not least on the list, should include a crossbow/compound bow with variety of arrow tips/arrows, a blowgun, and lastly - a WristRocket or similar type of slingshot - for those times when you don't want a "bang"