You should get familiar with ASUS Fan Xpert 2:
http://teksyndicate.com[...]
- which allows you to control fans.
I would suggest you to buy NF-S12B ULN as a top fan and run it @ 500rpm, hot air goes up. I was using for some time a solution with front + back fan and top hole covered with noise / heat blocking material and temperatures weren`t so good, +- 7 degrees higher.
I`m using 300rpm NF-S12B ULN fan on top of my case, and it helped to get better temperatures.
But you should definately do some OC, f.e. 4GHz 24/7, as you got really nice components, and still enjoy silence.
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P183 V3 @ 500rpm, P8P67 Deluxe, i7-2600K @ 4, NH-D14 @ 500rpm, 840 PRO 256GB, 8GB 1866MHz CL8, GTX 580 + Alpenföhn Peter @ 500rpm, SF 1000W Platinum