If I've learned anything from years on forums, it's that you'll always get shot down in flames for thinking outside the box, but it doesn't mean you should agree or follow with what people say.
Regardless, remapping a non-turbo engine is usually pointless, so I agree with the others; save the money and spend it on something better! The most you will gain is a change in driveability and possibly a change in fuel economy (and that means it could drop too).
You might gain a tiny improvement with a high performance air filter and exhaust.
If you really want a quicker 1.2 youd be better removing weight. Start with the spare wheel and any unwanted bits. Going to extremes you could pull off the A/C system and fit a shorter AUX belt.
Also, try running it on better fuel.
TBH I'd rather spend the money on suspension and tyres for better handling in corners.