French couple looking for an accomdation in Turku

Thomas and I are a french couple and would like a furnished apartment because we travel by plane. We know the colocation and use to live with other people. I currently live with 3 others person and know how to be. We are going to do an internship during 3 months in the University of Turku in partnership with our engineering school. It would be nice to live with person who like going out but also respect the privacy. We would like people of our ages (between 18 and 25). Thomas is a smoker but can smoke outside (or at the window) and I am not.