I have fitted several zetec's to kitcars and am swapping out a 1.8 pinto to 2.0 turbo zetec at the moment.

you don't need an aftermarket water rail unless your head is hard up the bulkhead like in a sierra. Oem works best.

Avoid the 1.8 cvh sump its workable but not worth the effort.

Starter. You have options. The only way the zetec starter can be used is by modifiying the bellhousing. You can use the pinto starter with a pinto style flywheel or a spacer.

the lrs707 is the bolt on solution.
The Sierra 1.8cvh and 2.0 dohc are the two donors. The difference is the position of the solenoid.