There are plenty of interesting e-ink e-readers on the market these days. If you prefer to type on such a device, you may want to give the Pomera a look. It is a compact device with a tri-fold keyboard and 6″ electronic paper display.
The device runs on batteries for 20 hours. You can replace them fast when you have to keep typing. Font size, line spacing, keyboard shortcuts, and other features can be customized.