Do I Sustain?

I'm faced with a difficult situation at the moment dealing with my responsibilities in the Church.  I am the president of the Sunday School and am charged with all gospel teaching during the second hour of our meetings.  In the training I have received and in the handbook of instructions it is clear that we are to use only the approved curriculum from the Church.  So I have been a little taken back by a special class for missionary work that has been pushed to be taught during the second hour that is not part of the current 2015 curriculum.  Earlier this week I received notice that it would not be taught in those wards that were not already teaching it or that had it scheduled to begin.  Our ward had neither of those so I figured it was done and I wouldn't have to worry about it longer.  Today in a meeting I felt a bit blindsided when it was announced we had approval for the class and that we would be starting it soon.  It was completely contrary to what I had received previous.  So what do you do in that situation?  It is a difficult thing to have to implement a class that I do not have materials for and that does not fit in the current curriculum.  When I orient the new teacher that will be called I instruct them that we should only be sticking to the doctrine and following the curriculum... except in your case.  It is a tough thing but alas, I don't make the big bucks I only raise my arm to the square and give a sustaining vote to those who are called to preside over the church in this area.  That said I will do everything I can to help this class be successful and to act well my part according to the instruction I receive from those over me.  Is that the wrong approach?  I don't think that it is.  I have voiced my concerns to multiple people over me and at the same time have resolved to sustain my leaders.  I have to swallow a bit of pride here and trust.  I'm sure it wasn't easy for Abraham to press forward with what he was asked to do but he went in faith and the Lord provided.  I will press forward and do what I am asked to do and will trust that the Lord will be pleased with my obedience to those who are in authority over me.