Migrating from NT4 to 2000

We currently have about 150 workstaions at 5 different locations. Each location is part of the WAN. Each location has its own server. We are looking to upgrade everything to Win2000. Would it be easier to upgrade the workstations (all NT) or to upgrade the servers first? Also we are looking to upgrade from Office 97 to 2000. Where should this fit in? Any suggestions? Also does anybody know first hand if AutoCAD R14 will run on 2000?
Thanks in advance.
Dave