Pure Kelpie's are fine, and fabulous companion dogs. They settle very well with a family, they do like a good run but are just as happy to lie around with company. We have a lovely chocolate kelpie and he is brilliant with our 2.5 year old, and has been very happy in the tiny victorian cottages in UK as long as he gets a social outing, cafe or park.
Be careful getting a welfare dog with children, you need to know their history, if you get a puppy from a breeder you know every experience they have had, and they know their place from the start of their life.
I also highly recommend a co. called barkbusters... they will charge a one off fee for the life of your dog and assist with family training and dog training anywhere in Oz... even if you move states! Our second dog is a welfare dog, rescued at 8months and he has a few phobias which they assisted us with.