Suncoast Porsche has the original version in stock......If you're willing to shell out $3000 for a new OEM set.
Boxster Sports Exhaust, 2003-04:Porsche Parts & Porsche Accessories - Wholesale Porsche Parts & Tequipment - Cayman Panamera Cayenn
These sre really hard to find second-hand or used. When they do pop up on eBay or Rennlist, they are gone the same day. They also don't stay in stock for long at the dismantlers either....I've been told LA Dismantler has a waiting list for these things.
Good luck in your search!