Still a bit work to be done but the system is already up and running, here's the current specs:
Coolermaster ATC-620C (black) case
Intel D865GLCLK mATXotherboard (integrated audio/video/lan)
Intel Pentium IV 2,8Ghz 800FSB processor
Coba 350W Power Supply (120mm fan)
2 x 512mb Kingston PC-3500 DDR
Samsung Spinpoint 160gb Serial ATA HD (SP1614C)
Plextor PX-708A DVD+/-RW drive
Hauppauge WinTV GO2 TV-Tuner
Processor is cooled by a Thermalright SP-94 with a bit of Arctic Silver 5 and a Y.S. Tech 80mm fan on top blowing AT the heatsink (the most silent one, can't remember the serial number right now). Would have wanted a 92mm but there weren't any great alternatives available.
One Nexus fan mounted inside the case onto the 60mm fan hole with a 60mm-80mm adapter sucking air out of the case.
You probably noticed that I didn't list a VGA card in the specs. I was going to install a 9700pro card with an Arctic-cooling VGA silencer but unfortunately the card was dead on arrival and I'm now waiting to get a replacement or some other card. The system is currently using the integrated video on the motherboard.
It's fairly quiet in my opinion but my last computer was insanely loud (you wouldn't believe how loud..) so it probably isn't as quiet as many of you would like.
One thing that bothers me though, is a very loud humming sound which I assume is coming from the HD and amplified by the case. The HD is mounted with normal screws and only from the other side since it's not possible to use screws on the other side in this case, so it's far from the best possible mounting.
I'm thinking of getting a Novibes or similar and mounting the HD into the free 5,25" slot I have left in the case, since there's hardly any space to do anything fancy with the 3,5" slot.
Temps reported by the Intel Active Monitor are CPU ~40C and system around 32C when idle. I fired up Seti@Home and the CPU temps rose to ~50C and system temps to around 42C. I think the temps are ok for such a cramped case, actually they're nearly identical to my old computer (the one that sounds like a jet

) with a 1ghz Athlon.
The Coba PSU has worked great so far! The back of the PSU has a switch (high-low-auto) which I keep at auto and the fan has been inaudible (about ~850RPM) even when the system is under load. All the voltages seem to be very good too.
Just a few random thoughts I had when I was building this system:
-The Intel guy who made the CPU retention bracket should be shot! It took me an HOUR to get it off the motherboard, one of the darn pins just wouldn't come off willingly.
-Assembling systems into mATX cases is harder than I thought, good thing I have long and nimble fingers
-The Nexus fan is a pain to install! I had some pretty darn long screws that still weren't long enough for the fan. I actually ended up using those black small wire things with a loop at the end through which you pull the other end to tighten them, to mount the fan to the fan adapter. Would have been thoughtful if Nexus had bundled the screws with the fan.
-I love Intel hardware

This was the most trouble free OS install I've ever had. There were literally NO problems (minus the small one below). No hardware conflicts, no software problems, no lockups, nothing. Quite amazing. Actually I even got my WLAN working in five minutes after it had been thoroughly messed up for years.
-I had some small trouble with the new Samsung HD. Windows 2000 didn't want to recognize anything more than 127gb, but it was solved by adding one line to the registry
-A nice surprise to see how software had progressed from the last time I built a computer. The chipset driver installation and BIOS updates were accomplishes by only a click or two, really nice.
I'm not really able to post pics since I don't have any webspace anymore and I'm not eager to get any crappy geocities accounts just to show a pic or two. The system isn't that exciting anyway even though I love the look of the case
I'm quite pleased with the system as it is, if I'd get the temps under load to drop a bit more it would be ideal.