I always wanted set of those

If you can get them for a good price, after 20,000 KM the Cat material shouldn't be used up. Just make sure they are indeed for the 2000-2004 Boxster and not 97-99 as (at least the outboard end) is smaller than the 2000-2004. Supposedly they flow better, etc. etc.
Looks like it comes with a free seized O2 sensor too