If you are looking for a powerful PSU that fits into any case and is extremely quiet then you definitely have to look at Sunbeam's Tuniq Mini Plant. While other companies use bigger cases and still have loud fans, Sunbeam has managed without both. In our testing the PSU can deliver the quietest experience we tested so far, in the 900W+ segment.
The only feature that I really miss is modularity. There are so many connectors included and you will often use only a few of them, so you are stuck with a large bundle of unnecessary cables. If you have a big case however it should be no problem to hide them.
The price tag of $250 is quite a big chunk of money, but it generally seems to be in range with offerings in that Watt range.