Every decent host OS already has a dedicated driver stack to provide game controller input to applications in a useful manner. Why the heck would you ship a reimplementation of that in JS in a website?
If it hasn't been invented yet, you don't need driver software for it, do you? ;)
Anyway, in your scenario the controller would be essentially a one off and you'd be better off writing a native app to interface with it for the one computer this experiment will run on.
