Upgrade from NT 4.0 —> Win2000

I currently have 3 NT 4.0 servers that Im going to upgrade. I have one new server that is 2000 waiting to replace my old file server.

The old file server is my PDC and I have 2 BDCs.
The question is:

1.Should I upgrade the current PDC?(totally possible with current hardware)and move the data and permissions.
2.Bring the new 2000 file server up in its own domain and then migrate the users from one to the other?
3. Other ideas??????
Thanks!!

Rich