Just to keep things simple, you may be best off using 2000 to administer your 2000 network. But to do some things, be sure to install samba on your workstation and you will be able to access file shares on the Windows servers. Another thing you may not be aware of but find very helpful is something called VNC. It's a cross platform protocol for sharing desktops, which means you can control the Windows servers directly from the Linux workstation.

You can download VNC from http://www.uk.research.att.com/vnc/

Good luck.