having not decided on a blogging service yet, I remembered that debian-administration.org provides a weblog. Sorry, that some of the references are in German.
Finally I started to look for the parts for my new desktop machine. You can take a look at the evolution for my choice of the mainboard here . The most important requirement is the probably soon implemented coreboot  support from Rudolf Marek.
So my choice is the Asus M2V-MX SE , which I ordered today at freeXpress  for 39,00 EUR plus 7,90 EUR shipping.
The only downsides so far are
- no firewire port,
- just 10/100 Mbps LAN Supports,
- just a VGA-port (no DVI) (wrong, edit: it has a VGA- and DVI-port --> so screw this item).
The machine will be sometimes used for video editing, so I decided to go with 4 GB of RAM. Because of the vast amount of RAM there are, I could not find a favorite. But reading the positive comments of buyers at K&M Elektronik , I went with the
4096MB A-DATA PC2-800 CL5 KIT (2 * 2 GB)
for 51,98 EUR.
For the processor my choice was originally the AMD Athlon 64 X2 Dual-Core 3800 + with 35 Watt TDP , , but according to  and  AMD stopped producing them, so they are not available.
Then I found in one shop the AMD Athlon64 X2 4050e , but the ASUS page does not list it as a supported processor. Therefore I went with the predecessor
AMD Athlon64 X2 BE-2350 EE Brisbane (ADH2350DDBOX)
for 61.76 EUR also at K&M Elektronik . Strangely this one costs more then the AMD Athlon64 X2 4050e.
I had to pay 5,99 EUR for shipping.
Now I will wait for the parts to arrive and I hope, that everything will work out nicely.