Quiet HTPC in Origen AE S10V

Hi Forum,

i want to build a very quiet and energy efficient HTPC based on the case Origen AE S10V.
A low noise emission is paticularly important to me as i have my desk next to the tv- and hifi-rack.
So how do i do it?
AMD or Intel? Which mainboard is best suited for HTPCs? How do i get it really quiet?

Any help is very much appreciated.

Greetings,
mikar

I didn't consider it important, but here goes:

country: Germany
budget range: 600-700€
approx. purchase date: next week
system usage: playing HD TV at 1080p, playing music at high quality (htpc -> external dac -> stereo-amp -> speakers)
parts not required: anything but the HTPC itself
preferred website for parts: www.hardwareversand.de
monitor resolution: no TV bought yet. but it's probably going to be a 42" lcd
additional comments: mainboard should have firewire and enough pci-slots for graphic card, tv tuner card and sound card.