I'm a little slow coming into the conversation, but wanted to add my two cents worth. First of all, paper work exchange varies, some breeders don't pass paper work along until certain conditions have been met by the new owner, such as spaying/neutering. Usually those conditions should be set forth in a contractual agreement between you and the breeder. If the breeder does not have a clear contract of what s/he will provide in regards to the pup; health guarantee, hip/eye certification information on the parents, shots/vaccinations, etc. vs. what you will provide; regular contact with breeder, additional shots/vaccinations, spay/neuter, etc. I would seriously consider walking the other way.
In regards to the cats, this is so totally dependent on both the conditions under which the pup was raised as well as the temperament of the dog (and the cat). I've seen lots of Siberians in the same household as cats, and both of mine are totally tolerant of the cats in my home. In fact the cats will often go into the crates with the dogs when the crates are open. That doesn't mean I would trust them to be good around other cats, especially if those cats were to run, as running often elicits the prey drive response. Do some research, find a breeder that has cats, and with whom the puppies have been raised around cats, make sure your cat will tolerate the dog (also a major factor), and you can have both in the same house without fear. Do a quick google search of Siberian huskies and cats - there are literally hundreds of pictures on the net. I personally would never allow ownership of cats to drive me away from the possibility of owning a Siberian.