Thank you for the answer, but the thread is talking about an engine swap.
I'm looking for a car and I want to know what engine is under the hood, I don't want that some guys sell me something that is not, just because I'm a girl; I have some knowledge about cars, but not a professional level.
If someone has the photos of the three models, and mention the differences on them, it would be
Because your question is about engines! And you were refered there for the pictures.
You'll find some pictures on google. (Google images FIAT Punto) Problem is, not a lot will be known, generally, about the specifications of cars exported to Tunisia.
As I say, the 16v engines look completely different to the 8v ones, so that's easy enough. Look for an 85, or 85 ELX badge.
The 8v SPI Punto will be a Mk1, almost certainly badged as a 60. The 8v MPI will be badged as a 75 and is also a Mk1.
But there will also be a Mk2 MPI cars with 8v engines.
[ame=http://en.wikipedia.org/wiki/Fiat_Punto]This[/ame] is an excellent -- and authoritative -- guide.