So I got my cat Shadow a couple weeks ago am considering getting him a friend. I work long hours, 9-5 at a preschool and then working at a restaurant on top of that a couple nights a week. He is a very active cat and I can tell he's been lonely when I am gone. Would it be good to get another cat to keep him company? Shadow is 1 1/2 years old. What age cat should I get if I should get him a friend at all?