Well like I said previously, if you're gaming you don't need an i7 at all, and these CPUs don't need to be OCd for games. I have a 2nd gen Sandy Bridge and I don't even need to OC this and I max everything out with a GTX 680. That being said, a stock 780ti will be more than plenty for 1080p gaming. To answer your question, you don't need anymore than 650w worth of quality PSU even IF you OC. If you want modular, a Seasonic M1211 620w or Seasonic G 650w is more than sufficient.
Any brand 780ti will be fine. I would stick to eVGA personally.
That Asus board is seriously overboard for what you need. You could save a lot of cash if you didn't go overboard on the wrong pieces.