As far as memory goes, I would buy a 1 or 2 gig micro card.
Also, I know this sounds stupid, but make sure your date on the phone is right. When I got my pearl, it said July 07. So everytime I got a missed call or text message, the phone would automatically erase it. Apparently I had the phone set to erase all messages after a certain date.
After I changed the date back to normal, all my messages came through...
Just a thought.