It's a good idea, though to be honest, I fear these "together apart" types of thing, you know? I don't think it's the same thing. Obviously, things are different. It can be rally useful if you're an ocean away, but I fear people use such things purely out of convenience, to watch together from two streets apart and just not get off the couch, you know? Which seems to me to reduce shared experiences.
I loved the header, and that sounds like a really unique idea! I can't wait to hear about the results :) Have fun with it.
Sometimes it is just enough to be in the same room, staring at the same screen with another :)