seeing as how i absolutely know nothing about your movie, feel free to take my opinion with a grain of salt.
i'd give the song a thumbs down though.
might i suggest looking into something more along the lines of sigur ros. not necissarily either of the songs below but... they'll give you an idea if you want to look into something like them further.
http://www.youtube.com/watch?v=P0AZIFmkogY
http://www.youtube.com/watch?v=okLCurB1lJw