Opel Astra J 1.4T Modifications

[Project xhr]

Good day everyone. I am based in Gauteng, South Africa. I was thinking of doing a special build on my 2011 Opel Astra J 1.4T. Initially I was thinking of swapping the 1.4T motor for the A20NFT from the OPC married to the the automatic transmission for that engine, but this would be a challenge as the parts for that transmission are not readily available in South Africa.

I then decided to try and rebuild my A14NET motor and marry that to an automatic transmission. Has anyone done anything like this before? Is it advisable to do? I am also looking to tune the engine from the standard 103kw 200Nm. But my questions is up to what point can I crank up the power without destroying the engine, I want the engine to have more kick without kicking itself to smithereens.