[ubuntu-uk] Ubuntu Server - sys req?

[Eddie Armstrong]

I am considering setting up a home server for streaming audio/file 
sharing etc and as a learning environment (for me to learn 
server-related stuff) .
I have looked on the Ubuntu site but can't find the system requirements 
for Ubuntu Server.
Does anybody know what they are?
I have an old PIII or I can use a Pentium 4 if necessary.
I would like to put XFCE on there in case I need a  GUI at some stage

Does this sound reasonable?
TIA
Eddie