Building a quiet and cool server?

[Ink Noise]

Anandtech community, long time reader, first time poster.

I'm in a bit of a pickle about creating the best cooling for my computer. Right now, this is what I have.

Antec P180 Mid-Tower Case
Intel E6400 Core 2 Duo
Intel DG965WH Motherboard
2GB PC2-7200 RAM
(2) 5.25" DVD+RW Drives
PCI TV Tuner (Happaugue)
PCI USB 2.0 4-Port Card
XFX GeForce 7600GT+ PCI-E
(w/ Zalman heatsink and low-speed fan)

Also in it are four 500GB SATA II hard drives. That's where the problem comes in. I use this box for Windows Media Center with occasion DVR use, but mainly to store massive amounts of media. It also acts as a network server for two other computers, is on 24/7 and the drives are read/written very frequently.

I am finding that temperatures are satisfactory except for the hard drives. I have two Samsung Spinpoint 500GB drives and two Western Digital Caviar SE16 500GB drives. During the daytime and under normal load, the Western Digital drives can get up to 125 or 130, and the Samsung get to 120.

So, what would be the best case to get if I plan on having this many drives and keeping them cool is a priority. I do plan on getting at least one more drive in the near future for a total of five 3.5" drives. Also, having a quiet computer is also key since I wouldn't turn it off when I sleep. Who can save me from have a massive hard drive crash or more sleepless nights?

Thanks.

EDIT: Forgot to mention that I've tried up to four 120mm fans and different placement of the drives in separate cages without much improvement.

 

[WoodButcher]

Can you space them out in the cages? One drive in every other slot to give each a little more air? Would you benefit from cutting a blowhole in the bottom of the case? Do the temps drop if the side is open? if so a bottom vent would help, any additional air intake will make a difference.