If you are require a native English speaker to bring your documentary to life, I will be happy to narrate it for you.
If it is currently in German, I can translate it for you into English. If you have written it yourself in English, I can also proofread it first. I have performed voiceovers for:
BBC World Service, Berlin
German Journalist Egmond Koch, (documentary later broadcast on the European television network, ARTE)Center TV, Bremen
Süd Ost Medien Agentur, Bremen
Weserbergland Nachrichten, Hamelin
You can hear an audio sample here.