First off all I would recommend a fanless powersupply, seasonic make some good ones.
SEASONIC X-SERIES FANLESS 460W PSU 80PLUS GOLD Is what I would recommend.
Yes, its only 460 watts - but its an EXTREMELY good quality PSU. I would happily run a gtx 580 on here, not with a full on overclock though.
Second of all you need too look into a good case. I would recommend a Fractal Design R3 - they have built this case with silence in mind. Extremely quiet, and noise dampening EVERYWHERE. It Has only 2x DVD drives though. best of all, they are cheap. I would replace the standard case fans with noctua ones.
You can run a 280mm radiator with this, which uses two 140mm fans (140mm fans are quiet than 120mm fans) You should use noctua p14 fans on this. I personally would take the rear fan on the case off, or just run it extremely slow - it will just take away air that could have gone through the radiator.
Lastly you should watercool your video card and your cpu, video cards make a lot of noise along with the cpu cooler. Using a decent watercooling setup with that radiator with 2x p14s should be adequate cooling, it should be enough too overclock a sandy bridge cpu as much as you need within safe voltages, and it will be better then stock cooling for the video card.
As for what pump too use, Im not sure, just google best quiet watercooling pump.
You should get a fan controller too, so you can control your fan speed. Most fans will push 80% of the air at 50% of the speed, running 50% quieter. (just rough estimations)
I would also run a SSD if you can afford it - hard drives can be very noisy - SSDs have silent operation.
I would love too build a pc like this and see how quiet it was!
It wont be DEAD silent, but its probably as silent as your going too get. If your doing audio work, then the video card wont be demanding much from the PSU so id be more then happy with a 460w.
Why dont you have a look in other studios and see what other people are using? Maybe your better off with integrated graphics. Your obviously not going too be gaming or benchmarking if its a audio studio computer, so you could even possibly look into a passive cpu air cooler. a HUGE one. Also the fractal f3 will look very proffesional in a studio.Edited by jacobrjett - 7/29/11 at 8:59pm