Speak with Mevris Ghostdancer in Val'sharah.
When the Legion was attacking, my partner went to Val'sharah to fight the demons.
Mevris may be cold and headstrong, but he's goal oriented, and willing to sacrifice to achieve them. That's part of why I fell in love with him.
If there is anyone who would know where we could get the raw materials for something of this magnitude, it would be him.
Head to Val'sharah, and look for him in the Temple of Elune. Tell him of our plan, and that we need his help securing scales.