if your aiming for 300kw there's alot of work that needs to be done. since your gonna rebuild ya engine get the head port and polish so you get better flow and the car becomes really responsive once you hit the pedal. metal head gasket is a good thing. go and see a guy by the name of harry at high octane he will give you a rebuilt kit including forge pistons and metal head gaskets. your probably lookin at $3000 for the kit. N1 water and oil pump. new timing belts while your at it. i work at chasers in melbourne if you have any other pm me i can give prices that we normally sell for down here. also get a new clutch. make sure its heavy duty. ya gonna need it for that power. also 550cc injectors, fuel pump, aftermarket computer, bigger intercooler. mate you be lookin at about $7000 and that's not including turbo. you should bring ya car to melbourne we can get you 300 kw at the wheels and explain it to you further.