That looks really pretty Claudia!
Laura O'Donnell did a Christmas one some time ago -
here. Using a floral foam shape makes it easy to attach the bills - just push a hairpin over the center of each fan-folded bill and into the foam. With a wedding topper rather than a Christmas one there's no reason you couldn't go with this shape. Or you could get a foam ball, mount it on a cane and make a topiary tree. You can make it look even more festive by tying ribbon bows (white organza would look pretty for a wedding) and using hairpins to attach those in amongst the bills.
Good luck with the project and best wishes to the couple as they start married life!