Hi fellow Holden employee! I'm also looking at similar mods to my car. I've already got the front de-cat pipe ready to be put on and plan to a larger VXR intercooler and EDS IPF unit to do an ECU remap.
I am having my mods done by Greg Stevenson at the Monaro Performance Centre who I got put onto by our performance products engineering group. He prepares many of the production based race cars Holden enter into events like Targa Tasmania and Bathurst 12 hr. He was the one who prepared the TS Astra SRi turbo Holden ran at Targe in 2003 so knows how to tune the Astra. On my previous MY06 SRi Turbo with no mods, he tuned it on the dyno taking it from 120kW at the wheels to 132kW at the wheels, while it is a relatively small improvement it was very noticable in the mid range.
By the way the 2.0l turbo family 2 engine in our cars comes from GM Brazil (not Brussels) and since the closure of our plant here at Holden it is the last GM plant making the family 2 engine. All other petrol non-turbo engines powering the AH astra are the slightly smaller family 1 engine. There is one exception and that's the 2.2l which is the new generation L850 family of aluminium block engines.
See you around!