Wouldnt bother with PC3200, save your dosh and get generic PC2700 from forums. Performance is not a big issue and I suspect your XP2200 wont clock far enough to get a decent 1:1 ratio going on the ram which you would need to make the most of it. 512 is more than adaquate for your needs I suspect.
If you must spend more get another hdd
, or a raid controller if the board doesnt support it for the two diamondmax drives