agusl, That's a good choice. Your feet may have stopped growing, but they do tend to spread a little while you are young. In my experience Lange tend to be a little smaller than other manufacturers. I think you may find them a little slack when they have packed in. That's nothing some thicker socks and maybe some packing where neeeded around the liner, won't cure.
To give you some idea of packing to use around a liner if needed check the pads and spacers out on the Togner site
http://www.tognar.com/boot_heater_warmer_fitting_dryer_canting_dryers_ski_snowboard.html
Trencher