I don't know anything about pet rats, but I do know that cats are excellent low maintenance pets, if you get a short hair and not a long hair. They're very loving, have a lot of personality and bond well with kids, unless you get a pure bred, in which case you need to do some research on which are best for families (Devon Rex is awesome for families and extremely playful, but range from adorable looking to slightly scary alien. And they're expensive.).
I know you said you're a dog person, but lots of dog people find out they're also cat people once they have one of their own (sort of like kids!). I love both, but currently have 2 cats because I don't have the time for a dog. My kitties are amazing wonderful company that other than food, water and litter duty, they take care of themselves, although I love to snuggle and play with them. My young nieces and nephews love them, too. Both were rescues.
Good luck!