Is FreeNAS 8 ready for production? or Any sugg. for a free fileserver?

I have two suggestions for you: 1) Try to isolate and understand what the actual problem is with the interaction between your Mac OS X clients and your Windows 2000 Server file shares. While it's probably a good idea to replace your Windows 2000 Server as it is no longer supported, you might not solve the problem. Maybe the switch is bad? Maybe is a problem with the way OS X handles the SMB protocol? Regardless, it would be a shame to replace your file server and not solve this problem (and likely introduce a few new ones along the way). Maybe start here with your troubleshooting efforts.

2) Get some old hardware and run FreeNAS. Do some testing and see how you like it...see how stable it feels to you. From this question it seems there are plenty of people running FreeNAS in a production environment. But the terms "stable" and "production" can have vastly different meanings and requirements depending on your environment. A little testing here will probably go a long way.