Agree with Phil. The lyrics are strong enough to stand on their own, and they don't need the prop of a "known tune", they deserve their own one, which would accentuate the right lines and syllables and match the feelings best.

Why, just reading the text, first off, a tune suggested itself to me. If you are interested, when I get a chance I will MP3 it and send it to you - just PM me with an email address to send it.