Style chooser

Hai, I am new here. I would like to have suggestions from all on upgrading the performance of a Waja 1.6(A) with bolt ons and without changing the engine.
Any suggestions anyone?

Current bolt ons:
Gab monoshocks absorbers + Zmax lowered springs(to change to Tein S-Tech
Ultra Racing Front Strut Bars
Pivot Volt Stabilizers and ground wires
17" rims + Silverstone tyres

In hand:
4 inch outlet firehill 2inch inlet + firehill header (need the advice and tips on the setting, cant do a...