Thanks all. Solid advice that I will take.

Curious as to why 5.56 ammo over .223? Is there a noticeable difference in accurancy and/or recoil?

Not sure I need 10 mags, but think this looks like a good deal:
1000 Rounds Independence 5.56 NATO 55Gr FMJ Ammo & Ten (10) Magpul 30RD PMAG Gen M2 5.56 Magazines