Thanks everyone for the replies. Great idea about commissioning a piece but unfortunately no time for that. Here's what we are going with next Saturday, ended up being pretty traditional, oh well:
Processional:
YouTube - Aria from Water Music Suite-Handel
Bride:
Berenice - Minuet From The Overture
Unity Candle:
YouTube - Bach's JESU JOY OF MAN'S DESIRING at the organ by Dudlei
Recessional:
YouTube - Widor 5th Organ Symphony Opus 42 No1 -Toccata