I've got the LN plug but it has only ever been torqued once as I haven't yet changed my oil a second time. ECS Tuning makes one now if you wanted try a different brand.
http://www.ecstuning.com/Porsche-2000-Boxster-986-Roadster_S-Convertible-H6_3.2L/Engine/Oil_Service/ES2587271/