When I homeschooled my twins, I made sure that they had the very best materials out there. I've got OCD, so I was organized to a fault, but I also made provisions for those days that I was having a bad day. On those days, the boys would read one of their novels, or work on math (Teaching Textbooks have lectures on cds so they could watch at their own pace).

Luckily the bad days were few and far between. It was really a joy to spend that time with them and hear their opinions on things. While doing history for example, what if this had not happened, how do you think things would change.

Or, as I mentioned in the gifted thread, look into virtual schools (I'd avoid K-12, just my opinion). You have the best of both worlds, kids getting an excellent education while being at home working at their own pace.