I'm in the same boat as you, RS762. I have both and regularly shoot both. Here's my 2 cents....
The pros and cons of 7.63x39 consolidation are as follows:
-5.56/.223 is far more abundant on this continent and will be around for a loooong time.
+5.56/.223 is more expensive than 7.62x39 which i have PLENTY of.
+I have very few AR mags, gear, and ammo wheras again, i have ALOT of Ak mags and gear.
+I am more practiced and familiar with the AK platform than the AR, and prefer the 7.62x39 cartridge in CQB circumstances.
-5.56/.223 gives me a greater ability to engage targets at range than the 7.62x39 ever will. 1. True, but don't think that cops/military will be handing out ammo in a SHTF. Look at Katrina. Also, if you have plenty of ammo already, you should start thinking about a realistic comfort level of what you stock. I set myself a limit of 2k for each rifle caliber. That's what's sealed up good and put away. I'll buy cheap stuff for training and replenish that as needed. If I can't get a battlefield pickup in 4,000 rounds, then I'm either dead or my sights are WAAAAY off.
2. Not always so. Surplus 5.56 is coming down in price, and 7.62 has been increasing steadily over the past few months. If you shop around enough, you can find good deals on both. I buy 5.56 from Palmetto State Armory and AIM Surplus when they have good sales. Check out Widener's for a kick ass deal on IMI 5.56.
www.gun-deals.com is also a good place to look.
3.
www.botachtactical.com Magpul P Mags. Use code "magpul" during checkout for 15% off. Free shipping on all orders. 12.73 per magazine to your door. You don't have to buy them all at once. Love or hate botach, it's kind of hard to fuck up an order for magazines.
4. Go with what you shoot better with. Also, if you plan on getting in to regular long range engagements for whatever reasons, sell them both and get a M1A.
If your woman is shooting an SKS, and you shoot the AK better, then you should stick with your AK. That doesn't mean you have to sell the AR. Get your self 10 mags, a case of ammo, a few spare parts and call it a day. Replenish as needed. You don't need to have 1,000,000 rounds for every rifle you own.
Just my 2 cents.