If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.
A NES outputs composite. Pretty sure an Intec screen does too, as well as RGB, and possibly S-Video. Search for it. (Be sure to select "Search for all terms").
well the quality is not comparable the psone is way better and smaller, also more people have worked with one so it would be way easier to use a psone because more people can help you with issues...