From my last count there were around 4 kits available for the Zetec engine. Only one of which we're sure will fit our cars. Most I've seen are for the Focus and that is typically where you'll find them. There was also one custom setuprecently that was supposed to be made available as a kit. His screen name here is '1TurboFocus' last time I checked.

www.focussport.com
www.focusperformance.com
www.focaljet.com
www.seanhylandfocus.com
www.focusparts.com
www.aerocharger.com

Those are a few good sites to look around for Focus related info and their available Turbos.