I am considering buying a P800 or P900 and am new to the PDA world. I've read that there are issues syncing up Outlook with many Symbian based phones. My dumb question is if Symbian 8.0 fixes some of these issues, can either the P800 or P900 be updated to the new 8.0 OS or can we only update firmware.
No, you can't upgrade the OS. New firmware versions have the same OS versions as the original. Technically, the manufacturer could do it, if the hardware capabilities are sufficient, but it hasn't happened with any Symbian phone yet.