I have a true dual s&s with screaming eagle mufflers, sound much much better

yeap dont like the 2 in 1 look for the a Ultra . any good local Melbourne suppliers ?

I run the std headers with the cat cut out and V&H slip ons with my 2012 Street Glide. I put the quiet baffle in them and have done over 50k with this set up. Told that the std headers with the cat removed are only a few HP behind other aftermarket headers costing $400-$600 on a dyno

Also consider s&s power duals. Khrome werks also sell one similar if not same as the s&s pipes.
Other pipes to consider from Yankee land are the fullsac headers and fuel moto 2-1-2 headers.
All of the above ideas are 2-1-2 pipes and should provide better Street performance than true duals
Some of the popular 2-1 pipes have a ghost pipe option to make it look like a dual system.

Monster Ovals by Vance & Hines, great sound and fill out the panniers nicely 

PLUS 1 on the monster Ovals, love mine

Just stock