I like to think of a basic sling wardrobe as the Chinese menu approach, i.e. one from column A, one-shoulder carriers like ring slings and pouches, and one from column B, two-shoulder carriers like mei tais/Asian baby carriers, wraps, and SSCs. With one of each category, your basic options and carrying positions are well-covered.
So I'd vote wrap.
Now, that doesn't answer which type of wrap.....a stretchy wrap is a lot easier to learn to use IMO than a woven wrap, but isn't going to last as long. A woven wrap definitely has a higher learning curve, and depending on your needs and comfort level might not be what you want to deal with for a newborn, but has more versatility if you put the practice into it in the long run.