As a self-confessed sling addict who has tried 50+ types I'd say:
Stretchy wraps are lovely for newborns. My absolute favourite is the Wrapsody Stretch, which is thinner but more supportive than the Moby - so cooler in summer, and you can use for larger, heavier babies. But Moby, Kari-Me etc will all do the job.
If you prefer the ease of buckles, there are lots of brands to choose from: Ergo, Manduca, Rose and Rebellion, Beco, Sleepy Nico, Connecta, Hoppediz Bondolino etc. Some are suitable from newborn and some from 3-4 months+. Personally I love the ergo from 5-6 months, but I don't think the infant insert bit is ideal, especially with a summer baby, as it can get very hot with it.
If you are petite, be aware that some brands of buckle carrier might not fit as well, as the straps can be too long.
If you can get to a sling meet, it's a great place to see some different things and try them out a bit to get a feel for what you might like. www.slingguide.co.uk is also a good place to start for looking at the different types of sling out there.