I'm 6'4 1/2" tall and I fitted aftermarket race type seats about 60mm rearward and a few mm higher than stock. It is a little cramped on entry/exit but once in there is plenty of room except I can't drive it with steelcaps on.

You can see in the pic that for the drivers side I just used a couple of pieces of 50x5 flat bar. Passed inspection in Qld.
Ideally you would move the seat back 100mm, extend the steering wheel back 25 and up 25 and raise the pedal assembly 25mm but that is just too much work.
Swift seats are quite good and are not bolt in but close. Others have used Pulsar/Astra or Barina or Honda CR-x or even Chrysler Voyager among others. A tape measure is your friend at the wreckers.
You are in W.A and I am not familiar with the modification approval process over there, maybe other W.A members will chime in.