Technology for Mortals

After much thought and consultation with a friend, I beleive that my persistently high hard drive failure rate on personal PCs (I average a drive failure every 6 – 9 months for the last 10 years, regardless of brand, model, etc.) may actually be caused by heat. So, I need suggestions on a case that provides lots of room for my hard drives to “breath”. My current case is pretty good about cooling, but the drives are still packed in tight, and my failure rate is a bit high (but lower than my normal history). Any suggestions (that do not involve pricey drive coolers) is appreicated! Must hold ATX MB, 4 internal hard drives, 1 – 2 5.25″ drives, and 1 3.5″ floppy drive (you never know when they come in handy).

J.Ja