Micro atx boards work fine; they just tend to have fewer overclocking settings in the bios. For amd, look for the 780g chipset with hdmi support. For Intel, look at the g43 chipset, which also has hdmi suport. If you don't need hdmi, there are plenty of low end boards with onboard video that will work fine. My other pc uses an msi g31 chipset board; they sell for around $65 new.