I like the idea of a 1000w psu. I have 2 5970s in crossfire and a slew of hdds. The 1000 watt allows you some leeway and I've had no problems whatsoever. The choice of case is subjective, your personal likes and dislikes,... There are a number of excellent choices. The 932 is one that comes to mind. Whichever one you choose, if you think crossfire is a future consideration, be certain to get one with excellent air flow, regardless of wc or not. Some cases can swap the fans for a better flow rate, depending on the size, the selection can be limited.
The people on this site can help you fine tune your picks with valid reasons why, so good luck and enjoy the new build!!!
