Radeon vega 64 for core V2 ?

Hello, I want to buy a graphic card that fit into the core V2 for both Windows and MacOs. My first choice was a vega 64 model but there are very wide, more than 52mm, and sapphire model is longer than 300mm (310mm). Does this fit into core v2 ? Has someone already puted a vega 64 into the core v2 ? Which model ? Is the vega 64 compatible with Windows? Has someone tested the new VEGA VII? If you can advice me a graphic card model… Thk