I'd suggest the Bushmaster ACR. Price is supposed to be $1500-$1600, modular design and construction (3 stocks, 3 forearms and a number of barrel lengths to choose from) so you can configure it as a SBR entry carbine (If you're willing to do the paperwork and pay the $200 NFA transfer tax.) on up to a precision/marksman's rifle and anything in between. It has ambidextrous controls, is 1/2 lb. lighter than a comparable AR, uses AR/M16 magazines, has gas piston operation and a quick change barrel system.

Another advantage with the modular design is they have plans to release conversions in various calibers including 6.8 SPC and 7.62x39 so you'd have even more versatility without having to buy or carry extra complete rifles. Myself, I'm planning on having an extra 18" barrel made in 6.5 MPC which is more appropriate for deer, feral pigs and black bear, (.223 not being legal for deer hunting here.) and only requires changing out the barrel as you'll see from the videos.

AR15 Shot Show 2008 video

YouTube-Future Weapons:Magpul Masada (Bushmaster ACR) video

Only drawback is that it hasn't been released for sale yet but it's due out sometime this summer.

I see no need for an Ar-15 or M-16 for a survival situation, even less so with a full auto one.

Yea they are fun to shoot and burn up ammo like crazy, but survival needs are better met with something else.

Russ, I do not own one (nor would I) but I have handled several of Kel-tec's other models. I have been around firearms my whole life, it is a passion of mine, and I can tell you just from observation of the design, materials, and QC in the Kel-tec line that it does not meet MY standards of what I want to defend MY life with.
I'll shoot cans with you all day long with one though!

If you want to see a cheaper light semi-auto (though not in .223) that I would stand behind Here ya go:
The Beretta CX4 Storm
9mm
.40 S&W
.45 ACP

(make mine a 40 S&W)

http://www.cx4storm.com/

Probably a nice rifle, but I doubt it's available in CA. That availability thing is a prerequisite to buying one.

They sell them at our local Gander Mountain here in Virginia.
Not sure what the laws are out there in the Peoples Republic of Kalifornia....lol

AR-15's aren't illegal in CA, but there are restrictions on how you can configure it. I can go out to my gunshop and pick one up today if I wanted to. In fact, a majority of the firearms aren't "illegal" in CA, it's just that some are much harder to acquire (legally) than others.

I would buy one of those. I'd like a carbine in a pistol caliber.

From the OP: Since he's in AZ, there should be no reason to settle for an SU-16 and I see no reason to go to a pistol caliber. Get a Bushmaster AR-15

Not true. There are way you can have a removable mag, or a higher capacity mag, or even some of the evil features like pistol grips with semi-removable mags, but at the expense of other features. So while you may not be able to get exactly the configuration you want, you're not as limited as you might think. It's complicated, best to do some research. A quick google will pull up a lot of sites like this.

http://www.paul.net/guns/CaliforniaRiflesU15.pdf

IMO an AR with a fixed magazine is useless; what's the point? FYI, at tenpercentfirearms.com one place they sell the MonsterMan grip is the following quote:
My three AR-15's are all "on-list" weapons so the lower receiver alone constitutes an assault rifle, let alone all the "evil features". Nahh, if it comes down to me needing something for HD, I'll use a 12 ga pump, the only evil features come out the barrel 9 at a time.