Hello Shabib67,
You will need to look at...Fuel,Oil,Water,Air( Intercoolerand turbo)movement and upgrade all these.
Upgrade your bottom end to RB30,get the motor dipped and cleaned.
Make sure you line the internals for oil movement.
Then port and polish,rebore,larger pistons,hks step2 or 3 cams with correct head gasket.
Go the single Turbo.
By this time your motor will be close to 3litres.
Crank(Shot pinned or upgraded"TOmie") and larger sump with baffle is needed.
If you are looking for a realiable machine,brakes,diff,gearbox,clutch,tyres and suspension all need replacement.
Then you need computer,boost controller and all the other things that go to making safe power.
Most of all ,as everyone has stated...$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$