try the coolermaster stacker. it has a 120mm fan front and back. also an 80mm blow fan at the top. the front fan blows across the hdd. you can also get a crossflow fan which is only used in this case. this blows cool air across the motherboard and ram. it is quiet except when on the highest level.look at it click here
I partly agree with harps1h: the CoolerMaster Stacker is a very good case. Large and expensive. This is because it can be converted to support the promised BTX format motherboards.
It also provides future-proofing which makes it worth considering against the outdated single/double 80mm fans which are totally inadequate for todays hotter 'go faster' components.
harps1h is not quite correct in the expanation of air flow for the top and side fans. They are both extractors - or should be. Installed the wrong way round will defeat the object by creating air vortexes inside the case resulting in the hot air circulating round rather than out.
In your research you will have used benchmark values against which to test.
The following are general benchmark values for measuring sound:
less than 22 dB(A)- inaudible to the human ear.
22 to 30 dB(A) considered to be 'quiet' and inaudible in the standard living room, because:
30 dB(A) is the backgroung noise level in the average living room.
38 dB(A) plus - noisy, with jet engine proportions after 42 dB(A).
You made the point about jet engines and I made the point about quiet.
All mechanically made noise is not necessarily audible to the human ear. Fans, for example, rotate at various speeds. At low speeds the sound frequency is very low, and inaudible at the very low end.
At the expense of boring everybody - I think you ought to give the BTX designers some credit for knowing what they are doing when they created PC cases that have lots of fans to keep the latest heat generating components cool and to keep the new PCs quiet.