I'd start with intercooler and hard pipeing possible egr delete if u want to not something that needs doing.
Exhaust system with bigger down pipe.
Replacement air filter with larger or custom intake or custom induction kit.
I'd replace the clutch about hear my slef. Or wait till it wears out or slips up to u.
Bigger turbo or hybrid depending on what power u want.
Injectors. Or injector nozzles once again depending on power wanted.
Them custom mapp to add all mods done and there u have one powerfull car.
Then after this your looking at custom exhaust manifolds and inlet manifolds.
And water meffonal injection.
I hope this all helps