I use a Palm IIIx. If the emails are short, then the Graffiti pen input is okay - otherwise a folding keyboard would make sense.
Palms synchronise beautifully with pc's.
The battery life is also pretty good - I get about 2-3 weeks from 2 x AAA.
I should certainly visit a computer where you can try both to see which you prefer - i.e. screen and input devices.
The Psion is also a fine PDA and would be my personal preference if I was going to be using it heavily.