I have these:
Not made in Oz but shipped to me in South Africa for not too much money using a u.s freight forwarded. A less than half the price of ripp, borla etc and although i dont have dyno proof they have definitely moved the torque curve down a bit for me making hills easier for the 3.8. I am boostec also and the headers came about a year after the blower. Bolted straight up (rhd like you) and been in for 35000 ks with no cracks or issues. I had them ceramic coated locally which turned out not so well as the coating is coming off in places. A custom tune will be needed to get the best out of them.
They definitely pump up the heat under the bonnet so I would strongly recommend bonnet vents and having them professionally heat wrapped with the best quality header wrap you can get before you install them. Afterwards is very difficult. Cheers