There are many great options out there. Here’s just what we do:
1) History: SCM guides, w/Truthquest History commentaries (biblical worldview). I think living books (including living spines/commentaries) are MUCH preferred to textbooks. I was an ‘A’ student, college-educated and can’t remember hardly a thing I learned about history. But I learn every day w/my kids in our living books:) Kids remember more if they care/are engaged.
2) Math: We also love Math-U-See. Have always used it and always plan to (8yrs. so far). The instructor gives a short video lesson that I watch w/my kids ea. week (funny, engaging, former math teacher). I help them with the first couple problems of new concept, and then they’re pretty independent. If your kids really struggle, I’ve heard Teaching Textbooks can be helpful.
3) Writing/Grammar: I’m using http://www.edudps.com/WWTB.html with my 12yo this year and next and it’s wonderful. You could combine both your kids in it. It’s to the point, helpful, and CM-friendly. For grammar, we use http://www.analyticalgrammar.com/. It’s pretty rigorous, but I like that it’s thorough in a short amount of time. You can just do it 10 weeks a year for 3 years. Or Our Mother Tongue sounds interesting (I just haven’t really checked out because I already own AG). If your kids need some spelling, we plan to try out SCM’s Spelling Wisdom this next year.
4) Science: We use Apologia. I think for college prep you can’t go wrong w/Apologia. But I’m not sure what to recommend if you have learning challenges (we haven’t gotten to h.s. level yet). I’m not familiar w/AIG’s h.s. level, though I must say I much prefer Jay Wile over Ken Ham. Jay Wile is a former college professor and is humble and open to other Christian views. Just my humble opinion:)
I hope you find peace in your decisions. There are lots of options to pray about. I think the more you learn about CM the more you’ll fall in love with her ways:) Blessings, Gina