I appreciate the effort you're making as I love watching these kinds of videos on YouTube. I've even contemplated making my own for the same reason you are, plus I just think it would be fun. My suggestion would be to buy them broken, be it locally or on the internet. Not that I don't think people are willing to donate, I just don't think many have a lot of consoles they have that don't work that they don't intend to fix. Perhaps you could offer to fix broken items for people and send them back and all they have to do is pay shipping?