I think its a lovely idea
, maybe post in legal & religous and you might get some replys or else do a search.
Best of luck
sorry i cant help I'm sick just thinking about saying the usual vows theres no way I'd manage to do my own
we're writing our own vows for our blessing i got an excellent book in borders published by confetti.co.uk it even has example vows and and glossary of words to use and structures to use and stuff about coins symbolising a whole solid valuable commitment really good defo don't feel so nervous about them now. well worth the money.