I like your idea of the handprints. I think they will be more durable and can be easily touched up or replaced if they don't stand up to time and wear/laundry. When there is an addition to the family, new handprints can be added. Make note of the person's name and how they are connected to the family. As to pictures--an album of the generations would be my choice as those will be protected and copies could be made for each family.