I'll spare the details of my initial setup -- I followed Jarod's amazing HOWTO (thanks Jarod). I'm running Fedora Core 3, with the Linux 2.6.9-1.681_FC3 kernel grabbed from ATRPMS using apt-get.
Antec's Piano Black Quiet Media Case
I decided to get a new case that's not a tower, and looks a little better on top of my entertainment center. Noise is a big factor too - I wanted the box to be very quiet, so I settled on Antec's Piano Black Quiet Media Case. The 380W power supply is absolutely silent. It's even got a washable filter in front of the air intake to keep it clean -- NICE. And, there's two low-voltage power cables inside to power the quiet fans.
The only noise coming from the case was from the 4 hard drives and the processor fan. It was amazingly quiet -- until I started having overheating problems. I decided to give the outtake fan on the right of the box full voltage to bring some of the hot air out, because the processor was getting up over 60 degrees Celcius, and the hard drives could cook a slab of ground beef. I wasn't happy about this, but it was necessary. The box is still pretty quiet.
I bought rounded IDE cables to further help the air flow, since the cables were right in front of the outtake fan.
Hauppauge 350 Card Overheating
Since I've been up and running, I've had two full lockups -- the whole system froze. It's been years since Linux has completely frozen up for me -- it looks like an overheat of the Hauppauge 350 card. The heatsink on the Hauppauge 350 would get extremely hot, almost burning my hand. It's no surprise, I'm using the card for the TV Out for both the mpeg2 TV recordings and for X as my primary graphics card.
So, to bring more air across the heatsink on the 350 I dropped a big fan in the box, blowing air across the PCI cards at low voltage to keep it quiet. So far, so good, but we'll see over the next week if this helps.