I need help looking for music like this

#21

Not as much classical but the Star Wars Republic Commando Soundtrack had some good pieces along the lines of what you seem to be looking for:
https://www.youtube.com/watch?v=t6gKLk-5QPw&feature=related
https://www.youtube.com/watch?v=iiNyQD5Yq3E
https://www.youtube.com/watch?v=B4dopv9TrvI&feature=related

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.