Why not create a choral version yourself Helen!?
This is a lovely song - Bette Middler did a very nice version of it I think.
You could purchase an inexpensive score-writing package for the computer (eg: Noteworthy costs only $39 - see www.noteworthysoftware.com ), purchase the sheet music (for piano say), enter the melody line, then add new parts and enter notes that would 'fit-in' with the chords for that note! Play it back, change it lots... eventually you'll have a masterpiece, you can extract each part from the score, print it all (after obtaining copyright permission from the publishers - they won't mind honest!)...
The big advantage of this - YOU know (hopefully) the standard of your choir (or you'll quickly discover it if not) - what you produce will most likely be achievable by them.
And you'll be as proud as punch when they perform it, especially when each part shows YOUR name as arranger and YOUR name is printed in the Program at a public performance!
Your head of music will be very impressed - and if you get stuck he/she will help you out....
Convinced?
Tell me yes!