Is it a v6 or v8?
Uv got the extractors, think about getting the exhaust system done. Holden CAI unit. Put a shift kit in, if its auto.. LSD for a better take off. Turbo = costly, cos ur going to need to prep the engine, if ur serious about it. You sound like a pretty young guy, so I wouldnt wanna do too much in terms of increasing power. Get some expirence on the roads and get used to the power and its possibilities in all different scenarios for ur own sake. Theres also what I would go with.. a bolt on supercharger, overall cheap and apparently a decent percentage increase in power.
Lower the car professionally, for better handling and just to alter the center of gravity of the car. Aswell, with any major power upgrades, might wanna think about brake upgrades.
Just save ur cash.. get something with a GenIII in it in a few years. I havnt really seen anything too impressive when it comes to V6s without ALOT of money spent on it. Same with vr/vs execs/berlinas/calais with the 5.0l in them.. honestly a decent V6 can keep up with one, that or the car Iv come up against arent that good.
My suggestion.. exhaust & a cai system to work with the extractors.. lower it also.