Polo 1.4 TDI Turbo upgrade and injectors

Hi there, today i start the quest to make my 9n3 1.4 faster, at the moment the little 3 banger has just a remap on the ecu, its not bad for what it is but my hunger for more power is still there, now i know that this engine is not the best to be modified as not many people have achieved more than 100bhp (which is what mine makes at the moment) but i cant see why not, its a PD100 minus a cylinder with a different turbo, so my question is if there is anyone in here that has done it before if you guys could shed some light in my path it would be amazing as the will to do it is there but i still have no clue if its going to work or not 

The engine in question is a BNM out of a 2006 polo 9n3 and the plan is to get the PD130 injectors drop those in, get a turbo off a PD100-PD115 cut one of the runners and modify to fit the engine, as i am a uni student price is an issue and reliability is another one, i know that i shouldn't be messing with it if i'm worried about reliability but i don't want crazy bhp numbers what i'm after is about 140 - 150

The short answer to that is to get a 1.9 as its the top dog for making it faster but i rather not because i don't want to deal with the issues of having to declare an engine swap and what not, plus the sound that the 3 banger makes is really nice.

so if anyone knows a bit of the topic please fill me in as i would love to do this little project but again there isn't a great amount of info out there, thank you for your time reading this !