Greetings, Matthias! Welcome to the V1 community.
Ryan did the beta cycle for LR4 including tubing options appropriate for builders all over the world, including beta team members in Germany.
Check out the LR4 beta program build log from @Tokoloshe , who I’ve tagged in this reply and who I bet can give you great guidance for your build and talk more about your tubing options.
I look forward to seeing your own build log and am curious what you plan to make with your machine.