@carls
I have built two machines in the recent months, both of them are mainly used for AmigaXL. I am very impressed with the motherboard that I used. I liked the first one so much that I got the same motherboard for the second one. I have on these machines QNX and AmigaXL, Winblows XP, and Mandrake Linux.
It is an ABit KX7-333 RAID mobo, and it is very highly rated. You can also get the same motherboard without the RAID controller chip...KX7-333.
It is rated very high on
http://www.motherboards.org and would be rated even higher but it has lost some points due to what some people consider features, but still a very good mobo. It isn't cluttered up with a bunch of junk. It is very straight up having no onboard sound or gfx, no useless risers, etc. It has 6 PCI slots, 1 AGP 4x, USB front and back with two additional headers, 1 Parallel, two Serial ports and PS/2 mouse and keyboard inputs, plus 4 memory slots. It can take up to 3GB unbuffered and 4GB registered. It uses DDR RAM, and I'm using PC2700 DDR on both machines. One machine has an Athlon 2200+ the other an Athlon 2400+.
It is a clean design, the BIOS is very good, plus if you're into overclocking it is very tweakable, basically an overclockers dream. I can highly recommend this motherboard, and it is not terribly expensive. I consider the lack of all the things it doesn't have like onboard sound, which can strip many fps off of games when it is being used, etc. a feature.

Anyway, it is a straightup motherboard, clean with no junk on it, and it still has some legacy support like PS/2, Parallel, and Serial. I did a alot of research on this motherboard and all the reviews I found rated it very high.
You can read the review at motherboards.org here:
http://www.motherboards.org/rank/AMD/total/motherboard-rank.htmlAlso, you'll find their other top picks here as well for Athlon processors. Again, this one lost points for not having onboard sound and gfx, etc., which some people consider a feature. I am of the opposite persuasion. I feel that the lack of this crap to be a feature.

Oh yeah, it doesn't have a built in ethernet card. Again, I find this to be a feature.

I forgot to mention that the motherboard is made really well...very high quality, and the RAID controller can be disabled. Also, you can use the RAID connectors as additional EIDE controllers if you need them.
regards,