Dont listen to Riven...manifold crack because
1. They dont install the brace(s)!!! Two brackets! one fo the 02 and one for the manifold.
2. Running higher boost.

I lean to stage3. Heres the trick...NO tuning required. With your mods & the toys kit, I can see 400 in your future.
Also if you are strapped for cash, you can buy the non-toys kit and get the toys simulator ( doesnt look as nice), to convert your non-toys to toys, for cheap.

I beat the snot out of my s3 and not a single issue. I can get 12MPG or I can get 32MPG.