Klaatu, thanks for the suggestions. Rest assured that I shall NOT buy any RAM from Apple Canada. My university's computer purchasing center buys Kingston RAM, and not Apple RAM.
Four years ago, when I bought my Dell Dimension, it was state of the art, and people thought that I was mad to initially buy 256Mb of RAM and the upgrade that to 512. This machine has paid for itself, but is now chugging along and will be "donated" to my son, who uses it as much as I do anyway.
Once the G5 arrives, I think that it shall be my computer for far longer than 4 years. We shall see.