I agree with R. I would more into reclaimed stuff than trying to make something new out of a “Green” material. I don’t know what there budget is, but trying to make a set of furniture for a restaurant out of these kind of materials seems like it would be very expensive. If you find chairs that have been used this will cut the cost down and could give the restaurant a unique style. You could also look into reclaimed wood, like from barns that have been torn down, etc… Good luck.