Welcome, Lewis. For this project, it will be useful to understand how Kinect's API for js works. Leap Motion's API is also available on the web, and that device is a strong contender for an input device. (There is a lot of information about the two devices on this list.)
GSoC candidates have been tackling some of the code exercises proposed in the thread called
Possible coding options for GSoC students
and other places on this list. Maybe soon there will be a new challenge.
Since we will be integrating gesture control into these interactive models, being familiar with the code behind them will be most useful.
As for your question about the device, we will support the chosen candidate however we can in in order to be successful.
Piotr is my co-mentor for this project, with more specific technical knowledge.
Best, -Nathan