What's Better For An 11 Year Old Boy, 'Karate' Or 'Wing Chun Kung Fu'?

Well, my nephew's parents wants him to take a martial art class and there are currently two classes in his area, the karate class takes place in 'Mornington Sports Centre, 142-150 Arlington Rd London NW1 7HP' and the teacher/instructor is called Greg who is from Africa. The Wing Chun Kung Fu class takes place in 'SAS Martial Arts Academy, Unit 2 Spectrum House 32-34 Gordon House Road London NW5 1LP'. Details Of The SAS Martial Arts Academy: Classes for adults and children in Wing Chun Kung Fu, Self Defence, Tai Chi, Chi Kung and fitness classes. Classes for children, Juniors working with government Every Child Matters outcomes, adult workouts with a holistic twist. (I Prefer 'Wing Chun Kung Fu Out Of These) .i would like to know everyone's opinion and the person with the most information and details will be chosen as best answer. Thank You :)