Trip from Buffalo, NY to Poland wedding

This is a 1999 pic of my adopted twins in Warsaw, Poland when they were 5 years old on the way to their new life in America. They were adopted into our family and raised with family values. Several years ago I found their oldest sibling Klaudia  in Lodz, Poland on FB and we have all connected. The other sister that was in the orphanage with my two lives in an institution and is severely handicapped.
Over the years I have connected with Klaudia and her son who I consider my Honorary Grandson. Klaudia is getting married Sept 7 and as our family representative I would like to be there for her, and if possible bring my husband.  I would also like to if possible visit the institutionalized sister for my kids.