I have a big furry girl too!
The chain training collars got stuck in her fur and would not release properly. She now uses a prong collar and it works great. I would hold off on it though, 8 weeks is a little young. I started Tink at 14 weeks with the prong after enrolling in obedience class. As a young pup, try the flat collar first and see how she does. Getting used to a collar at all is an adjustment for any pup. She probaly has never been walked on leash or anything yet. Start with the flat collar and mover her up to the prong when you think she is ready. But there is a right and a wrong way to use it. Educate yourself on them if you haven't used them before. Fit is very important.
Tink went through 3 collars in a month and a half. She grew soo fast. I would start with a 12"-14" adjustable collar,but don't spend a lot of money cause she will out grow it fast.
Good luck