I think the entire Age of Conan soundtrack was awesome, and would fit more than well in the Warhammer theme.
Some of my favorites:
https://www.youtube.com/watch?v=deDNzOYHu-4

https://www.youtube.com/watch?v=5Kn99vRCbww

https://www.youtube.com/watch?v=dQd4...eature=related

http://www.ageofconan.com/ (Go here and listen to the background music)- track 23. Combat Reborn –Cimmeria

Also-
https://youtube.com/watch?v=Ef5PJP1fsnQ

And

https://youtube.com/watch?v=e2Ma4BvMUwU