mas745,
I assume your building is 70' wide & 200' long with 20' bays. How tall are your sidewalls? If they are not too tall, say less than 20', why not make the endwall frame a rigid frame and eliminate the bracing in the endwall frame entirely. My experience is that the cost to make the endwall rigid is not a great deal higher than the endwall bracing, so it s a reasonable trade-off. If the building is a great deal taller than 20' than it does go up and might make the costs unacceptable. I am speaking about pre-engineered buildings here so if this is a conventional steel building I may be completely out to lunch in my suggestion.
Jim