Bosch Spark Plugs - Copper vs. Platinum

[dja1980]

I'm due for my first spark plug change, and I'm having a difficult time finding the recommended plugs locally. After doing some research, I found that the OEM plugs for my 2002 3.2L Boxster S are Bosch FGR 6 KQC. The problem I'm having is that even online, these plugs are somewhat difficult to find. However, I'm am finding a lot of the FGR 6 KQE, which I believe are the same plugs, but in Platinum as opposed to Copper. Are the Copper plugs superior to the Platinum ones in any way? If so, I've got a local import parts store that can special order them for me for around $10/ea. Otherwise, I will just go with the Platinum ones, which seem to be much more readily available. I'm sure Porsche must have a good reason for using the Copper ones as OEM instead of the Platinum ones. I also called the dealership to see if they stocked the Bosch plugs, but they told me they only carry Beru. I forgot to ask whether these were Copper or Platinum though. Thanks in advance for you help... dave