How much time do you have? That would dictate for me what quilt pattern to do. I would also choose a design I wanted to work on because I don't like working on a tedious or boring pattern. If you have time to pre- select a few patterns to show them, that would nice. Also you could scan some 1930's fabric and Civil War fabrics and see if they appeal to them. Myself I would lean towards the 1930 because of the variety of colours will match most paint colours. If you are a fairly good FMQ, you could do a whole cloth design on an all white/off white that would match with anything from vintage to modern. I love the texture and beauty of the vintage French white quilts!