I just bought the Ev3 kit, knowing that the gyro sensor is not included. I obviously want a gyro sensor, perhaps also the ultrasonic sensor. Is there any official channel to order them in Europe? All I can find is US-delivery-only and schools-only sites.
You can order the gyro sensor from the UK Lego Education site http://education.lego.com/en-gb/lego-education-product-database/mindstorms-ev3/45505-gyro-sensor.
If you look at the shipping options in the US Educational site, it will ask you a series of questions to determine if the item can be shipped to your area. If no other options are available, they will ship to you for a fee and ask you to approve the shipping fee before they send it out. It looks like you can get the parts from Lego if you want them bad enough.