There are quite a few companies that sell Classical homeschool curriculum. All of the companies that I am familiar with use a Christian approach.
Each company has a slightly different in philosophy. All believe in the
grammar stage, Logic stage, and rhetoric stage. Sometimes companies use a
different name for the stage.
In the first stage the child usually memorizes facts. In the second stage the child begins to learn to reason. The last stage is learning how to communicate their views.
Most companies have studies in Latin, ancient Greek literature, and logic. Christian companies emphasize church history.
Listed are three companies that I am familiar with.
Memoria Press sell Christian classical homeschool curriculum. You can buy curriculum packages for preschool through seventh grade. You can also buy individual books. There are books that are for eighth grade and up such as the Aeneid, traditional logic, and classical rhetoric.
Classical Academic Press sells books in Latin, Greek, Spanish, writing, poetry, bible, art, and reasoning.
Classical Conversations has developed communities across the country that will help you use the curriculum. They have three packages foundations for preschoolers through sixth grade, essentials for children in the fourth grade through the sixth grade, and challenge for children in the seventh through the twelfth grade. Some of the books such as their handwriting curriculum can be bought separately.
There are other venders that sell classical homeschool curriculum. I have received catalogs for Veritas Press and the Trivium Pursuit.
Veritas Press sells curriculum for kindergarten through twelfth grade. They have books for art, bible, geography, history, Latin, linguistics, literature, math, and music.
Trivium Pursuit sells several books that are written by the Bluedorns family such as the Fallacy Detective and Lives in Print. They also sell Teaching the Trivium. The book is about Classical Christian homeschooling.
Most of the companies have articles that describe how to use the classical approach in homeschooling.
The best book that I have read about how to use the classical approach in homeschooling is the Well Trained Mind by Susan Wise Bauer It describes the three stages of learning. The book goes into detail what should be taught in each grade. I remember when I read the book several years ago I was impressed with how she did a timeline and the lists of great books that each grade should read.
I have used classical homeschool curriculum with my children and have been happy with the materials.