Aiya Jacob .. i'm not evo sifu like Lanevo6, Lanevo, Leslie, Ben, Ah Kit, Azizi and a few others here laa ... i only started like 2 years ago only ... my knowledge limited ...
If me, i would do these few things leaving the stock turbo and engine internals alone ...
Intercooler (u can opt to maintain with your current stock intercooler) and pipings (customised is cheaper), racing radiator (better cooling) 272 cams and adjustable cam pulleys, metal head gasket (suggest since u going to change the metal head gasket, then replace the head studs also). Fuel injector to 650cc, fuel regulator, fuel rail, fuel pump (walbros 255lph cheap & direct replacement for stock). U may want to rebore your existing throttle body also .. since only slight increase, your stock clutch should be fine. if u want to change to aftermarket also can ... super single or hyper single ..
Of course, your ECU need a re-tune/re-flash ...
can check out the thread "how to modified to 400hp ..." in this section ... lots of different set-up ... cheaper alternative is something like the above that i would go for ..
Or u can do what Lancer7981 did .. he bought my camshaft adjustable pulleys and adj. on it .. by the tuner/mechanic ... but need a good mechanic to do that without damaging your engine ... basically advance the injection timing for more torquey feel ..