Music for the montage

We are finding it difficult to find some music for the montage. We want a stereotypical style of music used in montages within trailers, i.e strings or something along these lines growing in intensity. We are trying to find an actual track that has music we can use however we may need to use Garageband to compose a track. This may be problematic as it may sound too simple or not fit the style totally but we will just see how things will pan out.