Different content/templates usage for different languages

I have a client who now has five different websites for five countries/languages. The sites look the same and share a lot of content, but not all. For each country I have to be able to modify the page content, for instance, wether or not a certain block is visible or not, different images etc.

Is there a way/a plugin that makes this possible? Of course I could hide certain blocks with css, but that’s not how I would like this to work.