Both Zhou and Zhou are good Chinese characters and can be used for names. They all have their own meanings and sounds, and choosing which one suits the name better depends on your preferences and the overall style of the name.
Zhou (zhou) refers to a boat, and it can also refer to the people on the boat or sailing on the sea. Such as "flat boat", "light boat", "lone boat", etc.
zhou refers to a continent, or a vast body of water or land. Such as "Asia", "Africa", "Oceania", etc.
Therefore, if you want a name with a sense of flow, freedom, and adventure, Zhou may be more suitable; if you want a name that is vast, majestic, and steady, Zhou may be more suitable.