Ok, but the 10$ premium for the X2 3600+ is offset by the lower price of the motherboard. GeFarce 6100/MCP405-based motherboards cost less than 60$. GigaByte, ASRock and Biostar make them. Probably MSI too. ECS too, but, well, forget that one.
Chipsets for LGA775 : there's the 945GZ (awful...