I'm really enjoying our new sticky.
You didn't list gaming as a usage so I see no need to go there... but you have listed 4 monitors... Looks like you'll need something very specific there then.
You have to have cooling. You can avoid active cooling on the card itself, but you'll have to move air over it.
Probably this for GPUs:
HIS Passively cooled 4650
That would be a light gaming card that would probably provide moderate performance crossfired... you don't get any more without a fan or water cooling
You'll want a big, open case that can be configured to move a lot of air gently.
Cooler Master HAF
A good board that will take three video cards:
Gigabyte UD4P
(You can match these things on Amazon or wherever.)
Power Supply:
You don't need a lot here, but it should be quiet. You like quiet, so:
Corsair 650TX
For the CPU cooler you will want a Noctua:
Noctua NH-U12P
RAM - I don't want you grabbing the wrong set here, so I'll go to Amazon:
OCZ DDR3 1600 CAS 7
Hard drive:
WD Caviar Black 640GB