Welcome mate, enjoy your stay and nice pick up for your first Rex!
What's your budget for a cat back?
As Dave pointed out I can supply a Cat back system with a titanium muffler, these systems generally sell for around $1500 so $680 (limited time only) is a bargain but ill leave it up to you.
Titanium muffler will last longer than these cheap and inferior Chinese exhausts that are everywhere plus its lighter and gives an awesome sound.
Here's a pic:
Hijack over.
Cheers,
Wayno