I guess this means you can't do it.. I would suggest you get a girl to do it, that will keep people watching. Is angry around? Maybe he can get a hold of the chick who did the commander voice.. Or I would suggest you guy's goto a bunch of creative common's websites (like ccmixter.org) and post a thread asking for female(or male voice actors) to do the voice for the trailer because it will be free and they will do it just by putting there names in the credits. I am sure they would hop all over this too if you tell them its a game being released on steam and then tell them to check out steams webpage or something. Also, like if you goto ccmixter.org you can do a search for people who do spoken word poetry and hear basically a demo of there voice then you can PM them asking if they would be interested in doing this.
Damian, the dude who did the animations during 2.0 got some professional voice artist to do it for free. I doubt you'll be able to get a hold of Damian or the 'chick' who did the commander voice. There also might be a chance she won't do free work again.
How would any of those songs fit an empires trailer. The first one is just noise, and the second one is some kind of scifi dance song. Neither are good either.
NF voices should be done by mahti and frax I would like to help in any way shape or form. Getting footage, voice, writting the script w/e.
Nah I am pretty sure it was Angry cause I remember him mentioning the CC license, and the whole point of Creative Commons Licensing is to do free stuff like this to get your voice or music or art out there just to be in the credits. I am sure people would jump all over this since its a game that can potentially be played by thousands of players. This would be a lot of exposure for a voice artist. Seriously check out creative commons licensing websites like ccmixter.org