I have done ceiling mount before, turned out great! There are more options now than when I did it, so you should have no trouble finding some hardware. I also had two layers but I hung my heavy layer off to the side on decorative ceiling hooks, which seemed easier since it was non functional.

Are there other windows in the room that this treatment needs to jibe with?

Yes, there is one other window on the side. it's a standard window. This large window faces the front of the house. thanks