My computer isn't feeling well, so I can't refer back easily, but to Mom whose son is de-programming...
IMHO, the hardest thing for a new HS family to do is leave the PS way of life behind. A mistake often made by new HS families is re-creating the classroom at home. Why does he have to have a text book at all? Give him literature, good literature. A program our family enjoys is Learning Language Arts through Literature. It covers grammar, spelling, composition, handwriting and reading. Science, purchase some chem kits for the home, study the microscope or the stars, visit nature centers, national parks or the local pond. For history, well, I could go on forever. Our basic tools for history are a time line created by the student, a history outline almanac (ie. Kingfisher History Encyclopedia) and period related novels. You could build salt maps, put on a play, make a papier mache Roman helmet, serve a medieval feast... the ideas are endless. Of course, travel is always a plus. Visit some Civil War battlefields, explore the Alamo, study the Grand Canyon.
Now, math, well, that's a challenge in our home. And requires some text material. But there are also additivies..Critical Thinking Press books, Family Math, Whatever Happened to Penny Candy. There's also opportunity for a small business enterprise run by your child/ren.
Do a unit study on something your child/ren find intriquing. Somewhere out there is a spark for that love of learning. You may not find it immediately, but it's there!
I just re-read my words... Up at the top I said something about breaking free of the PS life style. I DO NOT criticize a families decision, whatever it is, (barring abusive behavior) in their schooling decision. To clarify, one reason we HS is because our child/ren learn differently. The nature of PS is to teach to a group. It's just the way it is. We as HS have more flexibility in that regard. Is it better? Sometimes. Right? For my family, yes, for yours? Only you can say. No judgements here, please.