I use the KJV, and I homeschool, because I know from my years as a Bible college student that the KJV is the most literal translation (from the original Hebrew, Greek, and Aramaic tongues) that is readily available. However, you could take that to another level and say only use the King James 1611 which is an even better translation that was translated prior to the current KJV. I also read English translations that are translated directly from the original tongues, and I have begun to see how the KJV has words added for clarification (usually in italics). I respect other Christian families who use other versions of the Bible. It is important to know why we do what we do and not just do it, because the pastor, another Christian, or someone we respect said it is the right thing to do.
There is nothing wrong with being old-fashioned in a modern society. However, legalism where the Bible is concerned cannot be enforced upon others. It is important to not only understand the letter of the law but the spirit of the law. Jesus Himself admonished the Pharisees and Saducees for demanding that others follow the last jot and tittle of the law, while they themselves did not believe Jesus was the Messiah.
I am a single homeschooling mother who homeschools my son and works from home. I, too, live in a big city where the influences are not the greatest--although I live in a good neighborhood. Do you belong to a church? What kind of support are you looking for concerning your children? Everyone is not going to believe what you believe concerning the KJV, singing only hymns, and dressing according to a strict code..
Perhaps your 6th grader's rebellion has to do with the strictness of his upbringing; he has to and eventually will learn to think for himself. The Bible says to train up a child in the way he should go, and when he is old he will not depart from it. This does not mean demanding that your child read the Bible and pray all day. This means offering spiritual guidance via the Bible, your example, and the example of godly leaders and showing agape love to all. It also means praying, recognizing the gifts God has given to your child(ren), and nurturing those gifts.
If you are waiting and expecting everyone who is willing to help you to be a conservative Evangelical Christian, you may be waiting forever. God works through people, and people don't have to be born-again believers for God to work through them. Your job is to ask God what to do, trust Him to lead you in the right direction, toward the right people, and follow His lead. Another part of your job is to pray for everyone in this world--even those who do not practice Christianity the way you do.
Concerning curriculum, there is Christian homeschool curriculum that may use other versions of the Bible in the text; however, you could choose to use the KJV of the scriptures; following is Christian curriculum information:
http://www.bedellcurriculum.com/index.htm (uses KJV)
http://www.shopchristianliberty.com/curriculum-kits/
I hope this information is helpful.