Been chatting to a few knowledgable friends and the standards ones are best. Everyone i know that says that Spitfire plugs and leads are useless and just avoid them as they are over priced.
Magnicor (sp??) do some nice leads for the k11 but they are nearly £100 for the set.
Basically the conversation ended with a agreement that Nissan did the job correctly and there is no need to waste money to different leads unless you go for silly power(140+). This also stands for the NGK spark plugs that are oem fit.