What is the most recommended PDA for a nurse?

I am a nurse planning to purchase a PDA to aid me in my profession. I would like it to be compatible with various softwares designed to aid nurses at work (drug guide, nursing diagnoses, etc..). I also would like it to work efficiently and be hassle-free, since most nurses really hate to be wasting time resetting it over and over. And lastly, I hope it has a generous memory to put mp3 files for me to listen to during breaks. I have been wrecking my head browsing over the internet for advice, but I think a nurse or someone in the medical profession can give me the best advice. thanks in advance!
... oh, and it has to be the latest model available, if that's possible... :)

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