Hi Ann,
I don't know if you are still reading this thread. But on the chance that you are, I wanted to offer some suggestions.
I think what you are trying to achieve is wonderful and a great idea if the family of your nephew is in the situation to raise a puppy. It take a lot of time, patience, and training. As a mother with three kids, raising puppies around kids who are dog savvy and without "special needs" is difficult enough.
Any responsible breeder and/or shelter/rescue group or service dog organization is going to first want to make sure the family is ready for and able to handle a dog in the home. The next step is deterimining what type of dog and whether a puppy or adult would be best. Personally, based on my experiences through the years with therapy work, service dogs, etc, I almost Always reccomend going through an experienced assistance dog organization. Raising and training your own runs the most risks of problems (and heartbreak if it doesnt' work out). Working with a group that has knowledge and experience behind them gives you a greater chance of success. Please consider this carefully and don't see it as a negative. I am saying this to help the family and child avoid problems. Not to discourage or offend you.
Therapy dogs and Service Dogs are proving to be very useful in working with kids with autism. That is true. Many groups do use Golden Retrievers, just due to their popularity in this line of work. A dog suitable for autistic kids needs to have the right level of energy, trainability, and Calmness for the situation. Not all dogs, and especially not all Golden Retrievers or Westies are suitable for the job. If the family you are trying to help Does choose to raise their own puppy and train it, they need to be extremely careful in selecting a breeder and subsequently a puppy. If they are not experienced dog trainers, which I assume they aren't or you wouldn't be asking these questions...then they will also need the assistance of a trainer to help in raising and training the dog. In which case, I also reccomend employing that trainer in advance of the puppy in order to help in the evaluation and selection process. A good trainer can also help you locate responsible breeders. Both Westies and Golden Retrievers have quite a few health problems, and some temperament problems.
There are plenty of responsible breeders around. I am in PA, and have a wonderful, very responsible breeder of Westies right down the road from me. I know of three great Golden Retriever breeders in PA and MD too. They do exist and aren't hard to find if you know where to look. Start at akc.org and located the national breed clubs for the breeds you are interested in. Then see if that club has a breeder referral program. That should help to get you on the track to locating a responsible breeder. Of course you still have to know what questions to ask and how to identify a responsible breeder who's dogs are Suitable to your needs. (for example as mentioned above a breeder of field bred Goldens may be very responsible, but his dogs might not be suitable for your needs) Once you locate a breeder who is willing to work with you, you need to determine if his/her dogs are suitable for you needs. Then you need to determine if the next litter you are eligible for is suitable. And finally you need to select the most suitable puppy in that litter. A trainer can help you with this process.
To get you started, here are some trainers who may be accessible to you and able to help you:
Maryland:
http://ljttraining.com/?page_id=2http://greenbeltdogtraining.com/http://www.fidosforfreedom.org/assist-dogs...information.phphttp://www.dogearsandpaws.com/And if anyone can help you or direct you best...I'll bet this person can!
http://www.peaceablepaws.com/Good luck in your search! It's important to recognize that this isn't an overnight process. The more time spent learning and studying, and then selecting the route to go...the more chance for success. I would still highly reccomend a trained, adult, assistance dog in almost every case and I think you need to carefully consider that option and the pro's/cons involved.