Converted old server case to positive pressure.
Removed a bit more metal than necessary, but surprisingly the bezel still snaps on on very securely.
Stock fans from my new PS07. (I took them out of that case when I put in Scythe 4-pin fans)
I put Silverstone FF121 inline filters in front of them. (you can't really see the filters in the pictures - sorry)
I drilled holes in the sides of the channel in the front bezel (which exactly fit the 120mm fans!) and fastened them together with the filters using zip ties.
I know it doesn't look like it, but there is actually plenty of clearance between the fans and the hard drives.
I may add a third drive hanging below at some point.
Both the rear fans are wired directly to 5v.
The 70mm Nexus cooler fan is wired to the little silver front panel floppy bay fan controller (generic from CompUSA years ago). I have a RPM wire going to the logicboard header and can see the speed changes in SpeedFan when I turn the knob on the fan controller. I have it running at about 1500 RPM and it blends/disappears into the overall white noise.
The front fans are also wired to the fan controller and blend well at any voltage.
The PSU is a FSP unit with a Panaflow swap connected to the logicboard PSU fan header (12v) and is currently the loudest thing in the system.
This isn't a very quiet system by any means, but it is fairly quiet and far cry from where it was before doing these mods.