We had an instrumental by The Corrs for walking in because its just a nice peice of music that we liked, Satelite by Dave Matthews Band because we love them, Yellow by Coldplay to walk out and we both love Ben Harper so danced our waltz to By my Side. We just sat down one day and went through our music collection and chose music that we loved and was special to us and refelcted who we are rather than looking at traditional and romantic music as such.
Good luck - its tough!!