We just started with a 7wk pup from a reputable breeder we know. We were able to watch the parents, and get our pick from the litter, so that helped as well. As everyone else said before, they are very smart, and full of energy. Unless you have them working on a task or give them a game to play, they will most likely take that energy into digging or running around the house with the toilet paper in their mouths as it flies off the roll...but once we tire out our pup, he flops down and crashes hard for a few hours.
If your kids are well behaved around dogs, and you teach them to not reinforce bad habits (like chasing after the pup), then I think you will have good success, especially with the land you have available. I think like the other poster above, your Aussie might end up being your responsibility after a short time, but if you dont mind, they are great dogs, but require a little more effort in the beginning while you are training them since they do have so much energy.
If your kids are well behaved around dogs, and you teach them to not reinforce bad habits (like chasing after the pup), then I think you will have good success, especially with the land you have available. I think like the other poster above, your Aussie might end up being your responsibility after a short time, but if you dont mind, they are great dogs, but require a little more effort in the beginning while you are training them since they do have so much energy.