I am all for turbocharged, mostly for the fact that they don't take up power from the engine but instead use exhaust gases to work, Turbo's are more reliable, placed properly with the right kit (Waste gates, Blow off valves, etc...) will give you virtually no lag, ball bearing turbo's are known to be better then pretty much any Supercharger weather it be Root Compressors, Lysholm Compressors or Centrifugal Compressors, how ever Superchargers do have the advantage of heat resistance over Turbo Chargers as Turbo's use Exhaust gases and secondly when air is compressed it produces heat as a by-product which makes the Tubro reach insane temperatures but that can be dealt by the aid of intercoolers.
Superchargers take up alot of power from the engine, for example theoretically a supercharger can take the output of a lets say 250 horse power motor up to 400 hp but practically could only manage 350 hp, the supercharger need to absorb 50 hp for its self to work, how ever in Centrifugal Compressors this issue can be solved to a bearable extent by adding an air to air intercooler as it will lower the temperature of the air entering the intake manifold, so because the turbo charger is able to utilize both the pressure and the heat energy of the engine exhaust gases with out taking power from the engine its is far more efficient!, Superchargers are suitable for bigger displacement engines (mostly larger then 4.0L, V8 territory, Large displacement engines usually use superchargers or 'blowers' because they have enough torque to spare and the power is instant (no lag), Turbos work well on smaller engines because they do not rob power and they can rev at higher RPM which is where turbos shine. But turbos have 'lag' because they actually restrict the air flow to the engine until they start to spool up, but not so much in the case of Ball Bearing Turbos, if you want killer acceleration and not top end power then Superchargers can do the trick but there is also a Turbo alternative to that problem, get smaller ball bearing turbo's (maybe a set Garret GT2871, smaller turbos especially Ball Bearing Turbo's have lesser lag and properly placed ones have instant power delivery, right off from as low as 1000 rpm, in comparison to the big boys like the GT42R or the bigger HKS or Exeddy turbos's), more over in a Turbo setup, less fuel is burnt off with the exhaust gases, so you aren't wasting any becuse the Tubro when idleing actually addamises the air causing it to burn better so you end up using all your fuel rather then it just burning away with the exhaust fumes, where as in a supercharger there is so much unnecessary fuel that is burnt with the exhaust fumes because it doesn't have anything to do with the Exhaust gases,
finally, Superchargers have a much more smoother power delivery, where as the Turbo's are much more aggressive, but top end power is what you get from a turbo and not from a Supercharger, Twin Turbo is possibly the best setup I can imagine, cost's a bit but is worth it.
and your AU$ 10,000 seems a bit tooo low for the kinda hp you're aiming for, especially since you' want to go down the bells and whistles (superchargers) road, the last time I checked, a base Stage 1 Comptech kit was costing around about U$D 9,000+,
in the end, I'd advice you to go for a Turbo Setup partly for the fact that its more reliable, more top and middle range power, higher rev band, nicer more pleasing exhaust note and mostly for the fact that your car is a 3.8 V6.
how much are you paying for your Supercharger?, they are overall more expensive then in comparison to Turbos.
