2.0 is basically the same but as it was only fitted in mondeos not escorts or fiestas, you need to fit the escort/fiesta zetec sump and pickup pipe so that the exhaust will clear the sump and not be pointin in a funny angle, then depending on the lump you pick you'll need the escort/fiesta waterpump as the mondy one spins the opposite way.

id get the 1.8 in and running to be honest. then when you get bored of that get a 2 litre lump and fit the 1.8 inlet with 2.0 throttle body and ecu and you can keep all the loom youve fitted... unless you 100% know what you're doing, then the 1.8 is the most sensible option.

focus blacktops can also be fitted but a lot of them have that PATS system which is a whole other pain in t'bum.