Have you tried the Fujitsu T2010 tablet? Battery life is around 9 hours on mine and loads from standby in seconds. If you scan or photograph your old journals into evernote (or onenote) you'll get portable handwriting recognition too, which could be handy.
Having said that, I'm going to give the irex digital reader or iliad a try, 3.5lbs is ok, but 1.3lbs is better!
I'm hoping the next generation of e-ink devices with 3g connections can work with the mobile web version of evernote, could make for handy mix.