You had your 'Line for 7 years? wow!
Anyway I've asked around and the NGK Iridium plugs are the best. They last 100,000kms and come in gaps of .8, .9 and 1.1mm. The model number for the RB25DET is BKR5EIX so I'll be picking up a set of these tomorrow for $18.50 a plug. I hope they go well...