What songs to play? String trio at ceremony & reception.?

So we found out that where our ceremony and reception is being held...they do not allow amplified music. We were not expecting that and had never even thought about it until we called to ask them what DJ's were on their approved list and they said, "um, none, we do not allow any sort of amplified music of any kind". Ugghhhh, well if that ain't a dilemma! I was able to find a string trio that a friend of mine highly recommended. On the contract they have a page where I am supposed to list requested songs. I have NO IDEA what to ask a string trio to play at our wedding. My fiancee was like....Metallica! I am like.....Rascal Flatts. ahaahha we have no clue, but would like to definitely have the music. Could you please give me some ideas of nice music for our wedding that can be preformed by the trio. Unfortunately, I am just not very educated in clical music! Also, what are some good ideas for the songs for them to play for my wedding party processional, my entrance and the recessional. Thanks.