Exhuast is: 1 5/8" primaries 900mm long, secondarys are 3" by 800 with a x-over into 5" supertrapps.
We made it ourself at a total cost of Aus$400 excluding the trapps.
Not sure how its going to perform yet as it hasnt been on a dyno yet... but common sense, EAP and some advice from here said it should work and be a decent balance between tq and hp.
We bought the flanges (thanks heaps to Elliotaw who arranged them for us. We salute you!), bought the bends from an exhaust place in sydney and measured the lengths on the car using pool hose cut to length. There are more pics of the exhaust here:
http://offroadracing.com.au/sorra/build_Wolf.htm