Maybe between the choir voices and the SA trumpet, you could do something like this beautiful arrangement of 'Cristo Rendentor' by jazz trumpeter Donald Byrd. It's long been one of my favorites. I've tried to do it before but none of the choir voices I had available to me sounded right. I tried it once with my church choir but Unitarian choirs are notoriously bad and it sounded like puppy poo. Maybe I can borrow a T4 .
http://www.youtube.com/watch?v=w2KvM2T40RQ

chas