Windows Server 2008 does not support Ukrainian language. The only entity that can add support for Ukrainian on Windows Server 2008 is Microsoft unfortunately. I don't think that this is about to happen any time soon (read never). If you stick with Ukrainian you shouldn't mix updates for Windows Server 2008 and Ukrainian editions of Vista. Russian is supported by Windows Server 2008 though and fairly similar to Ukrainian. I guess this is not an acceptable solution for you but just so you know.