...but Im a big fan of socket775 stuff for x86 based "amiga" machines. They, by mostly luck ended up a good balance between modern enough to have some nice grunt, but old enough to have some decent support.
Have Asus P5KPL-CM motherboard I need to try in Amithlon. is 775 based and I have a 3ghz Xenon Dual Core CPU for it. Am assuming that 1 stick of 1gb ram is the way to go for Amithlon kernel. Only 2 PCI slots though. But if Kernel 4 (Or Gary Kernel) picks up on Intel G31 + Intel ICH7 then everything good to go as far as basic hardware. I had a little PCI version 5200 video card but it died on me. Maybe I'll get another or something better so long as 2d/3d supported. And I do have a SB Live! audio card that could be used although I am not sure it would provide any advantage over motherboard VIA VT1708B 8 -Channel High-Definition Audio CODEC.