Here are my comments:
- The processors you're selecting are good and powerful (Xeon is for servers), however I would still invite you to take a look at something with 8 cores. In gaming, Intel outperforms AMD since most games are not optimized for multicore CPUs. But DAW software is VERY well optimized to take out the best out of multi threading, so in this case, more cores is better. AMD's 8xxx family is something you might want to take a look at.
- The cooler you selected is way too noisy. It's very efficient regarding air cooling, but it will make some noise, and you want to avoid that. Are you planning on overclocking? I don't think you should (overclocking almost always means more heat and thus more noise to cool it off), and if you don't, you don't really have to get anything more than the stock coolers, which are perfectly suited for factory clocks. If you still want to get an aftermarket cooler I would still recommend closed-loop liquid cooling. Quiet and efficient.
- I see you won't give up a powerful discrete video card. It's not ideal but I understand. However, the Radeon 7970 is known for running hot and loud. Nvidia on the other hand has been successful in keeping it's 6xx family running relatively quiet, I'd take a look at some GTX 670s if I were you, there are plenty of reviews and you can pick the most quiet (and performance is awesome). If you want to stick to the 7970, please take a look at this editorial:
http://www.tomshardware.com/reviews/deepcool-dracula-radeon-hd-7970-cooling,3246.html
- I'm not seeing any DAC (the single MOST important part of any DAW).. I'm assuming you have one already?
EDIT: - I was forgetting about your PSU. The one you're selecting will do, but to go the safe way get something with 80+ Gold or Platinum certified. It'll be more expensive, but the certification is about power efficiency. The more efficient the PSU is, the less energy will be wasted as heat (and less cooling will be required = more quiet).