Sounds like you have sorted out what you want to do and basically answered your own question.
The on-line Auto-speed magazine has a free to view all pages comparison of most mufflers available in Australia.
The 'other' muffler the guy talked about is a resonator, and that sits between the cat and the muffler.
Careful with your choice as many mufflers than claim quiet sounds are very flow restrictive and can be louder than straight through systems.
Autospeed listed the Genie Tornado muffler as best for flow and good quiet sound. They also said the Genie straight through Resonator was the best for that item as well.