Hi, heather. You can order Nails Inc. through Sephora online. However, whether or not a Sephora close to you may or may not have Nail Inc. in the store will vary from store to store. All Sephora stores carry different products in their stores, so the best thing you could do is to call the Sephora(s) close to you and ask them if they carry it in the store. Here's a link to the store locator so you can look up the phone number of the store(s) near you: http://www.sephora.com/help/stores/index.jhtml
Hope this helps!
Have a great day!