Ferrets are awesome pets, that it is very hard to find good breeders for. I was on the hunt for a breeder and found one that i thought would be good. She ended up being a horrible breeder, because due to bad weather and problems making out schedules line up she never sent my ferret, and even resold him. without refunding the money.
All 4 of my current ferrets are pet store ferrets, and all are healthy. the thing with most pet stores, they can't tell you the exact color of your ferret, but then it doesnt matter really. a ferrets color will get lighter or darker as it ages, and markings change too.
Most apartments don't allow ferrets because most people think ferrets stink horribly. If you find one that does, you are very lucky. I wish you luck in that
Ferrets do have musk glads, above their eyes, so they will always have a slight smell, though if you practice proper hygiene and proper nutrition the smell is much less. My own babies smell like their wood shaving bedding even though my mother hates them, and says they stink. Cages should have a full deep clean every week, and bars wiped down. cage furniture needs to be washed as well as their toys.
They CAN be litter trained but you cant use cat litter. they can inhale it and will get sick. My own ferrets have gotten respiratory infections, so i had to change from my previous bedding. They WILL burrow into their bedding so be careful of their eyes and noses. I've had my share of learning what is good for them and what isn't lol. One of mine is a persistent cage bar chewer. Discipline for a ferret can be difficult..only safe way is to scruff them. that doesnt mean pick them up and shake them XD Scruffing you just grab the skin at the nape of the neck and give them a quick shake, without lifting them up. nipping, biting, chewing things they shouldnt you can and should thump their noses as soon as they do it.
sorry rambling. lol