As Neil says, blue stuffs are pretty good on track. My preferred choice would be the Performance Friction 01 pads, but value for money the Blues are great. I'm only running around 300bhp on road tyres at the moment. I'm going to try slicks soon and I have a feeling I may need to upgrade to larger rotors, but we'll see.
I'm off to Blyton this weekend and have Rockingham booked on the 12th August (http://www.bookatrack.co.uk) - come along, it'd be good to meet up with more 350Z trackers.