This is the unit I used:
http://www.mgocspares.co.uk/ac..._Power_steering.html
Not an easy retrofit. I made a number of changes including changing the steering rack to fix bump steer; not just move it to a different range like the bump steer shim kit.
I upped the caster to about 7 degrees.
The nice thing is a switch to turn it on and off.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.