if your not going to use it for gaming or any 3d works, you dont really need to worry what unit you buy. the Eee pc seems nice and it a lot cheaper, you can first try reading some reviews about the unit, google it. my advice to you if your planning to get the eee pc get 4gb unit (not sure if this is the largest) and max the ram, i think it can hold up to 1gb of ram.
anyways, you should also check umpc, these are very portable compared with the eee, but its costly right now. i think asus have one, google it. get the model with the built in keyboard if your going to use it for office programs.