CPU: Why the 950? It's higher stock clocks but virtually the same CPU as a 930. If you get a good aftermarket cooler, you should easily be able to push it to 950 speeds using this forum
GPU: I'd recommend going with a GTX480 or GTX580 over the 5970 any day. I haven't heard of any complaints recently but I know the 5970 was plagued with driver problems, and single GPU setups are almost always *simpler* to maintain.
HDD: Get two Samsung F3 1TB drives for storage, and perhaps an SSD as your boot drive?
PSU: Get an XFX Black Edition 850w, cheaper and just as good if not better.
Mobo: I don't see anything wrong with those.
RAM: Let's see, I'd recommend 8GB for your use, no more. I'm not quite up to date with all the latest in RAM, having made a pretty bad choice myself, so I'll let someone else take care of this. Just, make sure it's no more than 8GB and no less than 6GB.
Sound Card: Don't need it. Those boards have integrated sound don't they?
Cooling: That should be fine to push a 930 to 950 standards.