I'm no expert so don't take everything here as 100% accurate!!!
Most people go for the T2 or T25, although the T25 is probably a bit extreme.
You will require a manifold to fit the turbo on to.
You will need an intercooler.
You will need a way of tuning the ECU, either STD ECU tuning or a piggy back ECU.
If you're going for a high level of induction then you'll need to look at forged pistons n other engine bits which others could tell you about.
May want to consider uprated fuel injectors, throttle body should be ok on turboing a 1L, but an uprated throttle body may be wanted.
Eds the Man to talk to on this as he done Nis's 1.4 Turbo and that hits over 200BHP