I would try the Jessica Harris method. My experience with sugar sheets is that they always crack and it's hard to line them up good on buttercream. If you have to adjust them at all it messes up the buttercream under it.
Another option could be to stencil it. Most hobby stores have various stencils or you could order one online and play with it before the wedding. With a stencil you could use buttercream, royal icing or airbrush.