For a not too expensive stash I would go with prefolds/flats and covers. It alot less difficult than it sounds
Am currently clothdiapering newborn and its prob my favorite and easy to costumize the absorbency.
I would go with about 10 Thirsties duo covers and 36 prefolds/flats, some boosters and 2 snappies
For a more fancy stash I would go with Thirsties Newborn Natural AIO