Herald Publishing House is the place to buy Community of Christ materials. Teaching resources, priesthood resources, worship resources also the Inspired Version of the Bible, Book of Mormon, and Doctrine and Covenants including just the Sections you may be missing from the Doctrine and Covenants you already own.

Herald House offers a few of their resources on Amazon as well. I have provided the links for the Book of Mormon and the Doctrine and Covenants below.