The same site I mentioned before has the option codes for the '01 std model, which I did not see the first go-'round.
http://industryfigure.com/berkeley/Porsche/Options/Options02General_10Aug01.htm
The list says for 2002 model, but then the list is headed 2001 model. I don't believe it has either the 502 or 584 options, however.
You can also go to the Porsche website (or PCA web site, if you are a member) and request, for a fee of about $90 as I recall, a Porsche Certificate of Authenticity for your car by VIN. It will list all of the options built on the car in plain English, but WITHOUT the option codes.
Googling "2001 Boxster option codes" with return something like 10,000 entries, so you can sort through those, too, if you wish.