I wouldn't be nearly as concerned with what brand of machine you get as I would dealer support since you're new. Go to a reputable dealer in your area and sit down with the machines and try them out. Find out what sorts of classes the dealer offers and how many classes you'll get for free.
I would say the minimum is needle up/down, either built in walking foot or a good separate walking foot and the ability to drop the feed dogs and the right foot for free motion quilting.