Warner Bros UK shop has posted listings for Godzilla: King Of The Monster Steelbooks, both have different art on the covers then what has been previously shown in listing so far. It is possible the art use previously was just a place holder, the art for the Steelbook with 3D and 2D version appears to be final while the art for the 4K version is pending approval. Prices in pounds are 29.99 for the 4K and 24.99 for the 3D/2D version, with other versions ranging from 9.99 to 24.99. No other info is listed yet but Michael Dougerty has hinted at bonus footage and the release is rumored for Sept 2019.
Update: these are also on Amazon in Germany with an Oct 31, 2019 release date.