You can probably cut back on the ram , you don't need 16gb , 8gb would be fine. You could take the savings and up the psu to a 750w just to be safe and be future proof incase you do SLI. Everything else is fine.
Is it gaming OR software encode stuff?
Corsair Vengeance 8GB 1600MHz low profile heatspreader $60
Optical Drive $20(Find one for $20)
Asus ROG Maximus $170
GTx 560 Ti 2GB $240
Antec 750w $100
Mid Tower $100(Find a mid tower with great airflow)
Yes, the AMD system is cheaper which would allow for a more expensive graphics card. The HD 6950 and GTX 560ti are about equal in relative power. However if overclocking is a goal, (and both the CPU's you mentioned are OC cpus with unlocked multipliers) then you should consider a quality motherboard. An 880G mobo would pale in comparison to the Z68.
For both of the games you've suggested, for maxing out at 1080p the GTX 470 is a better choice. One way to save money is you really don't need 16GB of memory for gaming under WIN7. It won't help with frame rates or image quality.
So either make room in the budget for the Z68/core i5 and go with a GTX 560ti and possibly sacrifice some eye candy, or go with the cheaper CPU and a GTX 470 and give up a little in frame rates. Most folks would tell you to go with the i5.