As said, if you are in Perth either XFT or Monsta Torque, I personally would go with Monsta Torque cheaper and better after care imo. But both are reputable. I am running the billet mustang shaft in mine and it is awesome. But I think you are under estimating by saying it can be done in 2 hours, it is a fairly large job! And if you are going to that effort then I highly suggest you throw a Allfast converter in it. Give you the stall speed, ability to lock or unlock it and retains the street friendliness unlike other converters on the market. It is also about 1/3rd of the price.
Also a Cyro intermediate shaft will be fine.