Considering a zetec to upgrade an escort, which year and models released in australia had zetecs?

A lot go for the 2.0L zetec from 2002-2004 focus (black top) Going price is cheap! About $400-$500 from the wreckers
 
Then allow $3K on retroford conversion parts to get it in an escort 
 
 

Retro-Ford's web site says that those sweet looking covers fit both silver and black top engines.

I've a Silvertop in my mk1 as well I've not driven in anger yet but seems fine so far. .. I'm going to turbo it soon and if it pops I'll go blacktop 1800, only cause I've 3 in my shed !

I would find a silver top. I had a blacktop in my mk2 and was shocked on how different they are. blacktop uses a totally different alternator setup, smaller hole in the block for waterpump aswell. silvertop has taller main caps. I believe the blacktop would be a better motor, just harder to do the conversion.

I had a silver top till the water pump fell apart and I fried it. Now have a 1800 Black top and love it. 

I have finished my Zetec black top conversion in my MK2 all when well parts supplied by Retro Ford in the UK