ideas about the dust problem
It's a matter of case pressure, or negative pressure. I had a case with a big 120mm fan in the back that used to suck air and dust into every possible nook and cranny. When I took a CDRW drive out, it had little dust drifts inside around the tray door and around the holes in the case around the drives. You should have negative pressure in the case to get the best ventilation, but the above is an example of going too far. A low-flow 80mm fan in the front blowing on the HD's, and a higher flow 80mm in the back blowing out is typical. If you want some really good and quiet fans, the Panaflo Low for the front and Panaflo Medium or high for the back. Many cases have additional vent holes to equalize pressure, so the dust problem would be minimized.
I have 10 fans blowing in this case, but there's an O/C Athlon in there that has to heat my room. :eek: