btw: The Chinese don't shoot AR's. Go for a ChiCom shooter. There will be plenty of ammo laying around to resupply with.
I chose the AK in 5.45x39. Some of my reasons are, the inherent reliability of the AK compared over the AR since it can take more dirt and abuse than the AR and still keep ticking. Plus the AR you listed would be a DPMS 20" rifle with it being an A2, you guys didn't realize that did you? For one I don't trust DPMS, for two I'd rather have the shorter rifle than a longer one for up close encounters. And I chose the 5.45 for lighter ammo than the 7.62, and yet more accuracy cause they normally have thicker barrells and are more accurate.
But then once I'd get home I'd have my 16" AR and use the AK for backup duty.
I think I would go with the AK. For one, I don't claim to be the best shot, nor the most experienced shooter, so long distance shooting is a non factor for me. I would want something that would run reliably and inflict the most damage at 100 yards or less. just look at the two rounds side by side, which one do you think would cause more damage?