Activity for Sara

I want to mail in my application to change my last name on my ss card. I know I need to send my certified marriage license but do I also need to mail my passport as proof of identity?

I was wondering what is typically less expensive: a small cake the bride and groom use for cutting pictures plus cupcakes/dessert bar for guests or one simple wedding cake and a grooms cake. We are estimating 125-150 guests.