If you really want silent IMHO the best option is a thin-client solution. Put a big old beast in a telco or climate controlled room (or shoved in your basement somewhere) and run hardware or software PCoIP or RemoteFX and use a thin client. No noise, no heat, not even that much more of a cost increase.
Winston, always good company! Hey kind sir, where is found good -simple- info on using thin-client, ballpark costs, how to attach 14 monitors; like that...? Thanks
https://en.wikipedia.org/wiki/Thin_client
https://en.wikipedia.org/wiki/PCoIP#PCoIP_Protocol