Finally replacing exhaust in my au2VCT

[SSD-85]

Good evening all, i finally want to replace my buggered stock exhaust in my au2 XR6 VCT, i chose the following setup:

Pacemaker Comp Headers
Redback 2 1/2 with metal cat

this does not have a rear muffler/resonator, only a centre. im not entirely sure if this is legal in QLD. im very curious as to what it will sound like. id like to retain it's low burble, if it ends up sounding like a buzzbox i will cry. : . any opinions/experiences would be great. also, what is the best oil to put in this car? i honestly wouldnt have a clue. :

[buickman]

To pass a honest roadworthy in Vic the car has to run at least 1 muffler in the middle and 1 at the rear.
The EB I purchased after selling my AU Ghia failed the roadworthy on not having a rear muffler only a tail pipe even though it had 2 centre mufflers.
My old AU VCT Ghia had Pacemaker PH4499 with redback system but I ended up replacing the redback rear muffler with my standed as the noise was a bit to hard to take after a very quiet car but when it rusted out I had a small hotdog fitted and it was legal when I sold the car and no problems with a roadworthy.
The sound a bit of a drone on the H/way but sounded great on full throttle.

I used Shell Hellix Ultra at 1st but switched to Mobil1