Standard Panda brakes will lock the wheels so there's no point going for bigger brakes.
That. The standard brakes are more than adequate for the performance.
The may lock but they will also run cooler and have less brake fade.
Neither of which is remotely relevant to normal driving in a 1.2 (unless you're planning to take it round a track)
You also have more control with a lighter touch than trying to gauge how heavy to stomp on the pedal.
Stomping on the pedal has no place in normal driving unless you are in an emergency situation
Jumping from the citroen to the fiat does give an initial thought of what's wrong with these brakes
Citroens generally have much more powerful servo assistance than most other cars, so pedal pressures are much reduced. Citroen salesmen often find customers on test drives brake much harder than intended until they familiarise with the cars. Personally I like Citroen brakes, but they're not to everyone's taste.
I'd agree that Fiat brakes often lack feel, vibrate, rattle, and snatch, but that's usually down to corrosion causing the pads to bind in the reaction frames. If they're in proper order, then you'll have no problem with braking under full control and there's nothing wrong with the feel or the pedal pressures either. If you are
experiencing any of these issues, then the brakes need stripping, cleaning and lubricating.
Ensuring the existing brake setup is in first class condition (discs & pads are cheap enough to change if there's any doubt) will gain you far more than transplanting a set intended for a different model. Doing this will likely involve replacing a lot of parts for no meaningful benefit. And that's before we start discussing the insurance implications.