Well....a good place to start is with something original. I think my whole year is just about doing the holocaust or pearl harbour, so if you can think of something else, you'll probably stand out more with markers. I'm doing Pompeii, so I'm using a piece from an encyclopedia, history, then using letters written by a guy who saw the whole thing, memory. Think of something you're interested in. You could even do something very recent, like the Bali bombings.
Something original, something you're interested in, and something that gives alot of contrast to eachother (remember you're playing the difference between history and memory)
Hope this helps!