Can one order a foreign keyboard layout in a US Apple Store?

Hey people! 🙂

Two yeras years ago, I moved from Germany, my homecountry, to the US. I have had my Macbook since 2008, so I just bought a new power adapter and it was all good. Unfortunately, my beloved notebook has become really slow at what I do for living (compiling, rendering etc.), therefore I decided to buy myself one of these new, shiny 15" Retina display Macbooks. I am programmer, so I have problably had billions of keystrokes in my life, and therefore know the German keyboard layout by heart. Switching to the US layout would probably take forever - not taking the fact into account, that I won't be able to do the German umlauts with just one keystroke. Unfortunately, the Online Store only allows one to replace the keyboard with a Japanese or a French one, which is not really helping me. I haven't had time to go to a local Apple Store to get information on that question yet, but does anyone know if one is able to order a different one the retail stores?

Thank you very much! 🙂