Effective FreeBSD installation on several servers

[Mikhail]

Hello, I have three servers which I'm going to use for dynamips setup, so I
basicly need only computing power of those machines.

What would be the most effective way to install/upgrade FreeBSD on servers?
I think about PXE booting through the network and mounting /,/home over NFS
- is it possible?

Has anyone done such thing before? Or maybe there are more effective way for
such installation?

Be well.