Don't want to give you a ****load of stuff to listen to, but I was thinking maybe The Blackening, by Machine Head would do. At first I thought it too heavy for Sheep, but it has a good amount of tracks that Sheep would find atleast mildly interesting.
Check it if you like:
Grooveshark - Listen to Free Music Online - Internet Radio - Free MP3 Streaming
I recommend Clenching The Fists Of Dissent and/or Halo. Also, the Battery cover is worth checking out as well.