Superb 2.0 turbo upgrade

I am looking to get more power out of my Skoda Superb 2012 170hp. Stage 2 chip tuning makes about 210 hp, so I want more than this.
Is there a bolt-on turbo from other cars that fit without modifications or is the hybrid turbo best variant?
And are the bigger injectors worth it?

There is no bolt on. You can get/make hybrid or go better with GTB/C/D turbos but needed welding. Injectors are not problem, but fuel pump - can make around 250hp.

As above, nothing off the shelf unless you go for welded turbo on stock manifolds...many sell custom kits with gtb/gtd/gta turbos and they work well although one can go with a tubular/custom manifold and a separate turbo for ease of installation. As above, fuel pump is the limiting factor and every tuner recommended cp3 pump swap for longevity...

I was thinking between two turbos GTB2056VK and GTB2260VK (and GTD2872VRK but this probably is overkill). Is the 2056 better choice because it is smaller, therefore, has less lag and I can't get past the 250hp mark anyway without changing the fuel pump? Or go with 2260? And do I need to change the actuator too?

Actuator should stay same, but vacuum converting GTB turbo means you need shorter lever. Depends on condition of pump maybe you get 240, maybe 270hp. If i was you i would take gtb1756 or 2056.

What type of 2056 would be best and what cars have this turbo?

GTB2056VK - i think Audi 3.0 204hp and Touareg. Or there is GTB2060vklr Mercedes 350CDI.

2060gtd or vklr would be my choice