Australian money would be awesome!! we got married in Canada but were heading back to Australia afterwards and one couple got us Australian money and I was so impressed it's cute and even though it seems inpersonal ..they will love it because they can use it for whatever
I think giving the AUS money is a really neat idea! It's really common to give people money for wedding presents, and this is such a cute way to help them enjoy their honeymoon. I would definitely give the AUS money. That's a really great idea!