It would seem that you and your dear husband need to work through the issues surrounding the differences in faith. When children are ready to be educated in the Catholic faith it is important that both husband and wife understand the total obligation to this task.
I want to clarify something for myself. Please bear with me if I ask a question. When you and your husband were preparing for marriage, was it necessary for you to discuss the obligation that a Catholic has to pass the faith onto the children? This may be something that has gone by the wayside and I am not aware of it. When my daughter married a lovely Methodist man in 2000, the two of them had to discuss this issue very seriously with the priest that was preparing them for marriage. He required a statement of consent from my daughter's fiancee, saying that he would not interfere with her desire to educate their children in the faith. This may be just a policy of that priest and not something required of all couples preparing for marriage.
Does your husband consider your faith as the faith of the children? If he does then it is understandable that you would want to educate them in the fullness of the faith through Catholic homeschooling, especially if you feel called to do so.
Let me ask another question. I thank you for your patience. Does your husband have an active and lively faith in his tradition of worship? Would he be against your using secular materials except of course for the teaching of religion? Perhaps this would present a common ground from which the two of you could begin a serious discussion about the faith. Many Catholic churches are having a series called "Why Catholic". This may be a good way for the two of you to begin a serious exploration of the Catholic faith for his sake. I found that when my husband converted, I learned a great deal from going to classes with him. Many times it is easier for someone to explore the faith, when they are with others who are doing the same. In this setting your husband may feel more free to ask questions etc.
Keep praying for his understanding. I do not know anything about the curriculum that you mention. I would prefer to use materials that I purchased from a teacher store or some similar place. I would not want to use anything that I hadn't read completely and approved. You are blest in that your children are very young and the materials that you will need are very simple. Though CHC materials are truly Catholic in their presentation they are not overwhelmingly so and I feel they would not be a threat to your husband's sensitivities. Go lightly into the purchases and let your husband see that the materials are peaceful.
I admire you very much. It is obvious that you have a deep love of your Catholic faith and your desire to pass the fullness of the Catholic faith onto your sweet children is holy and of the Lord. Go forward and pray for the Lord's guidance. Jesus will not fail you as He loves you dearly and this love is your empowerment. Go forward; you are going to do great.
Sending out a prayer,