Thanks a lot for the information, guys!
Some new questions arise; u-ATX fits in an standard ATX case, right? Does all of these chipsets use dual channel, so I should have a pair of dimms for best performance?
Here are some of the most interesting alternatives from some Swedish shops (ordered byt cost):
Asus P5GC-MX/1333, I945GC(A2),Socket-775 ,LAN, m-ATX, DDR2, VGA, PCI-Ex16
Gigabyte GA-G31MX-S2, G31, Socket-775, m-ATX, GbLAN, DDR2, VGA, PCI-Ex16
Asus P5KPL, G31, Socket-775, DDR2, ATX, GbLAN, SATAII, PCI-Ex16
I'd like integrated graphics to keep the costs down. But on the other hand the P5KPL-VM has less PCI and DIMM slots since its u-ATX... hmm