Default Where should I preorder the phone in Germany?

I wanna get the Xperia Z2 as soon as it comes out , but I don't know who will receive it the fastest? It sounds logical to order it on the official sony website but they're not saying when will it be available, you can just preorder it, while Saturn and Mediamarkt are saying it will be available on the 15.04, on Amazon you can preorder too, but there's no mention of the release date , what do you guys recommend? Where should I buy it?