Zen Xtra vs Toshiba Megabeat for audio books

Creative Nomad Jukebox Zen Xtra - MP3 Player - 60GB
and Toshiba Gigabeat MEG-F60S 60 GB and also Zen Vision M

This will be my first MP3 purchase. I would like to be able to use this overseas while traveling too. My main purpose of buying an MP3 player is to download a bunch of audio books from my library to use in the gym, in the car and while traveling. I'm not interested much in music. But I would love to be able to record something if I need too. It is important that it can be used interntionally without having to use power converter. I understand almost all electrical equipments now has that ability. Is that true?

From what I've read, Zen Xtra is very good. It has removable battery which is nice. I can have 2 batteries charged up for 20 hours plus flights. I'm not sure about Zen Vision M and Toshiba Gigabeat.

I need advice about what would be best for audio books. Is 60 GB too much?

Thanks!