Advice on a engine swap a3 1.9tdi

[Jake1998]

I am looking to swap the current 1.9tdie engine (105bhp) for a much bigger engine, I was thinking of going stage 2 but didn’t see the point when the output would be about the same as a standard bigger engine. Unless someone knows somewhere that does stage 2 that makes it much better.
I was just wondering if anyone has swapped one before or if anyone knows what engines would fit and what I would need to change to compensate for the bigger engine thanks.