According to the Huffington Post, the jacket was custom-made of silk jacquard necktie fabric. Looking at it, you wonder if it's a dress or a jacket. Taking off this jacket, which is perfectly tznua on its own, to reveal a gorgeous outfit would make such a statement. I think it's absolutely stunning and I hope Thom Browne mass produces it soon.
I wasn't able to find the belt on J. Crew's website, although it's very similar to the $250 Medallion Jeweled Sash.