Unless you are a conservative sensible sort of person who is able to be self disciplined then driving around in a small car like that with 300bhp sounds like you will be bending either the stock gearbox or something else.
Presumably the whole point of the upgrade is to live dangerously and be flashy?
I am a fairly boring man, car wise at least, but I have been unintentionally burning quite a bit of rubber lately in my 1.2 Punto. Your car looks like a stretched version of that. Can you really handle that amount of power in your existing car??