Can get 256duration 8.8mm lift cams which could be fine.
Above 8.8mm lift on a CA18 you need solid lifter conversion which adds bout 50% to the price, then you can go upto 10.25mm lift with still the relativley small 260 duration.

For me a RB30DET conversion is the best bet on any SX

Somthing like this, remarkably cheap too...
http://www.skylinesdownunder.com/for...threadid=40264

Its like a VERY basic version of whats going in my mota