I would go with a tank and a sceen on top, NO PLASTIC, gebils chew a LOT, and will chew there way right through plastic. they are neither nocturnal nor diaturnal, they love people, and sleep when they are bored. for bedding I would use sand, I did a project for bio and my results were that the more wild the habitat the vetter they are, the once kept in sand are way calmer and not crazy. they are also healthier, when cinnamon got loose she lived in the house with prditoes and made a nest out of whatever she found, she ate what she could find, and drand water from the dogs dish, when we cought her she was the healthiest gerbil I had ever seen in my life, and I am a former gerbil breeder. I recomend starting with a young gerbil, and start handing taming right away, they can live for several years provided they are from good lines, and properly cared for, I have 1 from my lines live to be 6 years old, and another that I sold to a friend, brandy, she died at 8 years.