Just one more note: It does not have to be wet food. They can get a well conditioned coat on just dry food, as long as it is the right food for them.
2 examples that I personally know of.
1) when Y.Lee came to live with me he had a dandruffy coat, but a couple of months on c/d (that's what mine eat) and his coat was shiny as anybody's. It is high in fat
2) a grooming customer of mine had a cat with a dandruff coat. It was also brittle and would mat rather easily, needed to change foods, and chose Iams. Same result......great looking coat.

the bottom line is finding which one is good for your cat, and most likely they can all eat it.