Another option in California is to build it yourself. Calguns.net has a good list of instruction for making sure you build a Ca. legal AR type rifle. Buy a CA legal AR lower and upper and componants. Or just buy a stripped lower and buy a DPMS or whatever upper. as for some reason the gun is the lower not the upper. Shrug.
True if you don't mind parts together. The CMMG .308 lower is off-the-list.