Welcome to the forum mate!
I am currently learning and working on a project my self, but as of yet I still need to pass my driving test. I know a thing or two about the tuning and what's what.
Jarrus is our resident derv head, anything you want to know about IDI engines he knows. He should be along very shortly.
Induction kit will actually have no benefit at all with our engines, best to do would be buy a replacement filter that goes in the current airbox, as it is a good design. That will see you better.
A full decat exhaust system will remove the restrictions of the silencer and dreadful cat, this will also help with turbo spool too, add that to your list.
What you will need to find out are:
-What fuel pump your running.
- What turbo your running.
To determine the turbo, get underneath the car, behind the engine and with a light, you should see the turbo. If it has an acutator arm that means its a Garrett t2, if it has a black hub sort of thing, its a KKK.
Next thing would be, before any tuning of the fuel pump, or turbo would be too install a boost gauge.