Where can I find sheet music for Prelude 2 by Dustin O'Hollan?

I particularly like this song and I really want to play it. I don't only want the piano music, but violin and cello sheet music since I heard this accompanied by those instruments. I've already tried searching Google and using the Google advanced search but I can't find the actually sheet music. If there are no pieces available for this song, can you please recommend me a really good song for a trio of violin, cello, and piano? I want to play a sad, but beautiful piece.