You don't need much Irshad, once you've got the exhaust then do the following:
1 bar restrictor ring
Boost controller (Manual or electronic)
Free flowing air filter such as the Blitz LM panel filter.
Decat
Fuel Cut Defender
Colder spark plugs, such as Denso IK24
If the SMIC is in bad condition you'll need to either replace that or get an FMIC.
It's also recommended that you upgrade the fuel pump or even just replace with a new stock one - it's cheaper to just buy a Walbro pump and have that fitted.
That lot should get you there easily and beyond, the restrictor ring is just to restrict the boost but I have read various things saying that they aren't required on a VVTI as the wastegate is stronger and doesn't overboost like the old non-VVTi one but I don't know if that's right or not.