I've been sampling a lot of music specifically for this project and I've narrowed it down to some possible candidates:
Stand Up - Trapt
Run - Snow Patrol
The beauty of these kinds of songs is they are so vastly different, but they emphasize various aspects of the film in different ways.
For example, "Run" is more of a philosophical, deeper exploration of some of the ideas the film explores while "Stand Up" is a literal exploration of fighting the totalitarian regieme with lyrics like "I'll finish what you started when we come face to face" -- Which is perfect for "V for Vendetta" is so many ways it's really errie.
Also, I scoured Youtube to see some of the "V for Vendetta" videos for inspiration and ironically, these two were already done... But to be honest they weren't very good in my opinion and were typical of most videos you find on the net with scenes going on way too long and no real editing taking place. As a result, I may just redo one of them the proper way... Or, maybe not. We'll see...