Well, there is one computer that will do all of that now. I'm thinking of buying one, but also looking into a slightly larger version. The downside, as with any true portable computer, is battery life. This supposedly gets 5 and a half hours, and the battery is small enough that you could pack a second. It doesn't weigh all that much more than an Iliad ... however, again, battery life is less.
But, it has a write on screen, in vivid color, is not much bigger than your typical ebook reader .... although it costs 2 to 4 times more than your typical ebook reader.
http://store.shopfujitsu.com/fpc/Eco...do?series=U810