Aha, that is some nice cross-engineering there!

The gearbox should bolt straight on to any old Zetec (starter motor at the front of the engine), but there are other things you might have to modify, two of them being alternator bracket and gearbox/engine mount, if I remember correctly. Just search the forum here, it has been done loads of times.

That Escort/Fiesta engine I meant is a 1.8 16V with 130 bhp. The normal 1.8 from the Mondeo has 115 bhp. You could also go for the 2.0 16V (136 bhp) from the Mondeo. This will have more torque but will be less revvy because it's the same bore as the 1.8, only stroke is longer.