Hi! I'm building HTPC/media center from the spare parts - e8400 Core 2, ATI 2600XT Passive, 4 1TB Green drives and Corsair HX520W PSU. It will be sitting just few feet away from a viewing place, so has to be as quiet as possible.
Initially I was going to buy PC-C60B from Lian-Li, under-volt everything, damper the walls and be done with it, but then while browsing I've stubmled across 6000B nMediaPC case:



and I was struck as how much it resembles my ACR 520, which is going to be sitting on top of it:
http://forum.ih8mud.com/attachment.php?attachmentid=576307&stc=1&d=1322436325
- same black slotted steel, same acrylic panel, same size. Overall they seem to match each other very well, so I've started to consider getting myself an nMedia case.

I couldn't find any reviews other then this one:
http://benchmarkreviews.com/index.php?o ... mitstart=1
Given that amount of noise is critical, will it be possible to build something good out of it if I replace all case fans. (the case is very open)

It's a sturdy case, so vibration from the fans shouldn't be amplified. The fans in the back are 80mm, the side fan is 120mm all easily replaceable if necessary. OCIA's review finds them quiet.
I'm unsure how good the drive decoupling is, but I guess for 5K drives it should be ok. If you undervolt or replace the fans, this will most likely be the main source of noise. Even with 4 drives it should be very quiet.