This is the first time I'm buying a Palm and I don't know which one I should get.

I have narrowed it down to these models:

Zire 21:

Pros: The least expensive of the models. The battery pack suppose to last longer than the other models.
Cons: Monochrome colours. No expansion slot.

Zire 31:

Pros: Colours. Expansion slot.
Cons: Resolution isn't that good.

Tungsten E:

Pros: Better resolution. Music and video. Expansion slot.
Cons: Most expensive. I have been reading reports of units breaking down after the 90 day warranty!

I won't be needing the Palm to:

-Surf websites
-Send e-mail
-Phone people
-Play games

My Palm Requirements:

-Keep track of due dates, to do lists
-Looking up future dates and past dates for scheduling
-Take down notes
-A long battery life
-Keep track of contacts
-Easy on the eyes to read
-Keep a log of daily events

Can someone please give me advice and recommendation on choosing a model.