PDA: Which one and what software?

Hello, I am a private pilot aspiring to move up the rating and get my
CFI.

I am in the market for a PDA to help organize my life, dates, phone
numbers, addresses, emails, and also double as a electronic flight
computer and sort of a electronic flight bag type of thing.

My laptop is a Powerbook Mac and my desktop is a PC.

Should I go with a Palm pPilot (OS) or a Pocket PC? And which have
better software for aviation?

Sorry for the basic questions, but I am a total newbie when it comes to
PDA's.