I hope to be in the right chapter.

Hello everyone.
I am French and I come to you to have some information.
I bought a Ford Fiesta mk1 and I want to change its engine.
I think of mounting a ZETEC engine with its 5-speed gearbox. I would put a 2.0 liter but harder to find.
Is it the same mounting for a 1.6 or 1.8 liter zetec engine? These engines are easier to find in my country.
I think it's better to take a Focus engine, is that correct?

Can you give me any modifications to be made on the Fiesta?

I would ask you to be as clear as possible because I use Google Translation and I want to understand what you are saying.

Thank you for all the information you give me.