I received some information a while back--that the Hardy/Minnis/H&W powers-that-be have explored the possibility of a 7/8 oz. Fresco. Which, for those late July/early August days here on the East Coast, would be most welcome. But, alas, we'll see.
Halstead Explorer is a superb 8 oz. panama. It doesn't receive as much attention as it deserves. I think there's a blue-gray in that book.
Back to H&S: The Cape Horn HighTwist book is a bit more polished that the Cool Breeze. Only a 1/2 ounce heavier, and 100's. A different finish, smoother to the touch. Still, a basic wear-a-lot summer panama.
I've petitioned for a lighter weight version of H&S Crispaire. I feel sure if they included a small run (a few solids and basic stripes) of 8/9 oz. Crispaire in the book, it would sell well. Crispaire is great for what it is but there's no way it's a mid-summer Manhattan cloth. I have 10/11 oz. panamas that are more porous.
One can easily imagine a blue-grey in a lighter weight version. So many kinds of potentially great cloth.