Look for "Over-the-Shoulder Baby Holder" or "Maya Wrap" on Google. I'm pretty sure Over the Shoulder is sold in stores like Babies R Us, and I know Maya Wrap has a web site. If you're in contact with La Leche League, they probably have them to sell or have a list of sources. I've never been very successful at nursing with the sling (maybe because of my robust figure :-), but it's wonderful for carrying them around, especially when you have several walking, too!
Don't miss the chance to hold your baby! I wish I'd been more appreciative when I had my first one (or two)! I've got pictures on my profile page, but the one of James is pretty old. I bought him a couple of 12-month outfits at the secondhand store yesterday ... one is too small, so I'll give it to someone at church on Sunday!
And do you have clothes from Motherwear? Even a couple of shirts, or the excellent nursing undershirt, will make it much more comfortable for you to nurse in public. They last really well; the shirt I'm wearing today is on its 4th baby, and just starting to get a little worn on the seams.
What cute kids! I will start looking online for slings!