Well here is how I would do it.
Setup a server or two with NIS and NFS sharing /home, /usr at minimum.
Use gigabit networking, and since it is say ... less than 300 PC's, stick with a small subnet, like 192.168.0.0/24 or so. And use DHCP for sanity ... ;D
Another possible change would be to say fuck it and go thin client. If you have the server (RAM and HDD space) it would be REALLY easy. Netboots ;D