Do you want it upgradeable for future processors and RAM? Does it need onboard video, sound, LAN, or SATA/RAID? Does it matter if it supports the 2000+ and the RAM but nothing further than that?
If ya can fill out the LasQuestionaire then it'll narrow it down a lot. There's a mobo on NewEgg that'll support your processor and RAM for $26.
As for chipset...if you're gonna spend $40-$60, then it doesn't matter.
-Lasereth