Any cast iron is IMO vastly superior to the wire grates for grilling. I happen to have a rectangular grate that is a perfect fit for a 22.5 kettle.
What I particularly like about it is the bars are 3/4" tall and spaced very closely.
I also use the CI grate from my Lodge Sportsman's Grill on an 18.5 kettle.
I'm thinking about a Craycourt for my charcoal Go Anywhere.