Thank you this is what I needed to get a second opinion on =)No idea what you're talking about with the Xbox bit but 750W is fine for CF 6970s.
http://www.legitreviews.com/images/reviews/1488/power-consumption.jpg
6970s only came in at 600w under load, 150w is more than enough for overclocking headroom.
I'm keen to see how this turns out.

