Hyundai never sold it here

Yes, almost universally. The Veloster N shares the i30 N's engine, gearbox, turbo and most of its hardware, so intakes, intercoolers, downpipes and exhausts listed for the i30 N (or Kona N / Elantra N where noted) bolt straight on. That shared parts pool is the main reason a grey-import Veloster N is easy to support.

A tune. The Theta II runs conservative boost and timing from factory, and an ECU flash unlocks the most gains for the least money — typically lifting it well past 220-230 kW on the stock turbo with no other hardware. After that, an intake and a turbo-back exhaust are the usual next steps.

With a tune plus a decent intake and exhaust, mid-to-high 230s kW at the crank is a sensible target on 98, with a big lift in midrange torque. The factory turbo is the ceiling — chasing more than that means a turbo upgrade and supporting fuelling.

The early 8-speed DCT can be hard on clutches if you tune aggressively and launch it a lot, so keep an eye on fluid and clutch health. The 2.0T itself is strong, but the factory rod bearings don't love sustained high boost — sensible tuning and good oil habits go a long way on a hard-driven car.