I am thinking about getting a puppy. I need a puppy that is good with kids, playful, low mantice, good with cats, and stays small forever.?

dream well tonight for this is the only place you will find this dog

you need a stuffed toy.. all dog are maintence needs. vaccines spayed chipped ER hospital vet wellnesd check. food etc.

A stuffed one

No dog is low maintenance
No puppy is good with kids and kids are not good with puppies. Toy breeds are the worst with kids

Poodles are great. They are smart and can be playful. They don't really she'd and toy breeds can stay small. I recommend getting one from a breeder.

Maltese, shihtzu, yorkie, lhasha or bichon. They may need the occasional haircut.

It depends on your lifestyle.
Good with kids:If socialized at young age to be with small kids you should have no problem.
Playful:All dogs are playful.
Good with cats:If introduced to a kitten at young age you should be fine but if your cat is old and is used to dogs that is ok,but if your cat isn't good with other dogs you might have a small problemo.
I would recommend the australian shepherd but they are very active that's why i said it depends on your lifestyle are you going out and having time to play with your dog?
They are medium sized dogs but they can also come in smaller size.

It depends on the age of the kids. Many small or toy breeds are too delicate or prone to BITE/NIP for young kids.

The very BEST breed for kids is a Golden Retriever. It is NOT low maintenance as to coat, or small but it is gentle, easy to train and very friendly, usually good with cats if raise WITH them. Poodles come in 3 sizes & are lower maintenance but have to have professional grooming (which ain't cheap). They are higher energy than Goldens, may or may not all be okay with cats.

What about a French bulldog, a Boston Terrier or a Beagle?

If I were to get a dog, I'd get a mini poodle. My friend has one and it's very smart. Also, it's an adult but it's so small it still looks like a puppy.

Poodles
Shih tzus
Maltese
bichons
Small mutts (mix breeds)
Chihuahua (good with cats but not always with kids)
Norwich terrier
West highland terrier
Yorkshire terrier
Silky terrier
Give these breeds a try.
Remember though when introducing with cats, make sure you do it properly especially around terriers because in some of my suggestions I said a few terriers and terriers tend to pray. Also I think it's best to get a mutt. Mutts are the best since there mixed

Rotilier.