Chris,
Defencemodels.com has a resin update set that includes the cannon and turret, corrected exhausts, rotor "chinese hat", new accurate wings and the sensor turret. The intake covers are also included, but they don't look like any I've seen on the Aussie Tigres as of yet.
The set ran me $40USD including shipping, which was a bit steep. You're lucky, the kit here is the Italeri one, which the update was designed for. The Revell kit is crap.
A warning to anyone wanting to do the conversion, USE THE ITALERI KIT! The old RoG kit is completely inaccurate and the tail is TOTALLY wrong. After many maddening hours trying to beef up and correct the tail, I've shelved the project for now.
Jon