I know no one can be sure will the limited information I have on the server, but I was looking at a school surplus and saw some servers I was interested in. The were dell powershots and some had p4 processors other has Pentium D, and 1 had a xeon processor.
They were the rack mount kind and only 1 slot tall not the double slot.
Anyone have a guess of how much power (watts) it will take to run on idle?
I wouldn't hazard a guess and can't reach to pull one out of my server at the moment but I can tell you there's almost certainly more than one so the system carries on running if one breaks down. Also, it will be a special - bot the usual 450Watt box you pick up for £25 in Maplin so if the server you buy doesn't have one, it could cost you more than the unit itself to buy the right one.
By the way - go for the Xeon.