I'll be honest, from your post my first thought was to just rehome the dog now while it's still a puppy. It's a lot easier to find a new home for a dog now instead of when it's 9 months old, big, and in the hyper puppy stage. Regardless of breed, it's a puppy, it's going to mouthy, playful, etc. can you handle that with a baby? As Karen said you have plenty of time to train the dog which will help, the dog should easily be potty trained by then (I'm assuming the dog will be in the house not an outdoor dog?). Have you had dogs/big dogs before?

I would say either breed can be great with children but neither breed is one that I would necessarily recommend to people wanting a dog good with children. Aussies are herding breeds which tend to nip/herd other animals/kids...not that they are trying to be mean but if you don't understand herding behavior it could cause a problem. They also have a LOT of energy and need mental stimulation, they need a "job" to keep them occupied.

I don't know as much about akitas but most that I've met tend to be dog aggressive (which does not at all equal human aggression but something to be aware of). They are protective of their families and strong willed/stubborn. If they are anything like my huskies in temperament and I think they are similar in this sense, they do things based on "what's in it for them" not "I want to please my owner."

If you take the time to train and socialize your pup it can be a great dog, ANY breed can be a great dog. I would definitely make sure you spay/neuter the puppy at around 5-6 months and start a puppy training class right away. Also remember to train yourselves ha ha....you are responsible for supervising interactions with the dog and the baby, you have to make sure the baby is not going to hurt or startle the dog which could react in a bite. Even the best dogs who loves kids could bite if a child was hurting it and of course a baby doesn't realise it's hurting the dog by pulling its fur, poking it in the eye, etc. When the child gets older you have to teach the child to understand how to be safe and gentle around a dog. That sounds like a beautiful dog, do you have any pics?