I just put my processor up on eBay since I got rid of my machine. It's an 800Mhz chip with 2MB of cache and it works great. It's a cheap way to make an old G4 very enjoyable to use.
Here's the eBay link..
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2759152566
Let me know if you have any questions...