Since I can't find anything in the HCL, I'm asking here:

Any motherboards that you'd recommend? Looking for an AM2 one. In the 90$-130$ CAD range. (80$-120$ USD, 50-90 euros-ish) All the ones I've seen seem to not work with Ubuntu, my distro of choice.

When I look for motherboards, I usually find out what the kernel supports and then look hard at the pictures of each motherboard. The drivers that the motherboard brand provides also gives clues what hardware the motherboard contains for NIC, storage, and graphics. Rarely you need to figure out the hardware that it uses for on-board sound because all of them are handle through PHY, so modules like snd-intel8x0 or snd-hda-intel will work just fine. Any motherboard will work if the desire distribution uses kernel version 2.6.19 or higher. If it has a lower version, you may need a PCI NIC until you can upgrade the kernel.

I suggest looking at either ABIT or Gigabyte. These two brands provides better support for Linux than other brands. People disagree because ASUS motherboards also work which is true on some of their boards, but you pay a premium price for a low quality board and manual.

AM2 sockets is fine, but there is catch on processor selection. The multiplier have to be even instead of odd because AM2 socket processors only uses integers not fractions for the multiplier. I suggest looking at 939 socket motherboards because you have a wider selection of processors and the memory latency is a lot lower than DDR2. Some people may disagree on investing in 939 socket motherboards because it does not have any future. This is true, but AM2 also does not have long future until K8L processors comes out which will be a different socket.

What's K8L?

So bascily AM2 is going out the door as well?

I'll check out some S939 ones, then, thanks. But do they support DDR2, and the AthlonFXs?

No, 939 socket motherboards do not use DDR2. DDR is better because it has lower latency than DDR2. Read my previous post again. Really there is no advantage of using DDR2 for AMD systems or for any computer setup. The following links explains in detail about DDR2 latency, the multiplier issue, and news about K8L.

http://www.anandtech.com/cpuchipsets...oc.aspx?i=2741
http://www.anandtech.com/cpuchipsets...oc.aspx?i=2762
http://www.anandtech.com/showdoc.aspx?i=2768&p=3