Tbh, you will likely have issues trying to get that cpu to work. It may or may not, theres no articles clear online that answer anyones questions about it. They get a direction and thank the posters and never update the thread with the result.
I do recommend and back up stardude82s suggestion to get a new mobo and cpu. This will likely cause you to need new ram, which can get expensive but will be guaranteed to work and will be a better performance boost. The X2 6000 isn't a bad chip, I still have one, but its not as good as what is offered in the current line up of cpus,
If you buy any cpu with that same socket, you are likely to experience problems booting and lack of support for BIOS updates to make it work as your system was designed for the buy it and throw it away later consumers. I mean that from an upgrade standpoint and am not trying to degrade your system.
Whats your reason for upgrading? Gaming, movie playback, multitasking? List your current hardware specs such as video card, ram, OS and the like so we can tell if it will make sense to upgrade the cpu.
I just finished repairing a system for a buddy of mine and he has a system with the same cpu. Windows 7 and a video card set him straight and hes happy for a bit longer...