I would go with #1 or #6 (I voted #1). When my daughter was born at 7lbs 11 oz her little waist was still too small for even the preemie/newborn size pants so I would choose something that's one-piece.
1 but mainly because I think it would be the only one that even fits. Most can wear a premie outfit home and everything else is usually (not always though) too big.
Quoting s a n d r a:“ wow so most newborns wouldn't be able to fit new born size pants?”
None of mine did and my son even weighed almost 9 pounds. They all came home in premie outfits and so have all the babies I have seen. I know not ALL everywhere do but a good majority.