Or get one from a modern Corsa, it's a bit in the middle of the steering shaft and has a motor on the side. It has a fair few wires as it has a seperate ECU to register speed and stiffness of the steering, but you don't really need this, just 12v igntion and earth (the ECU is attached anyway).
If you're interested, there's been a green Corsa in Cheshire Car Components which is on River Lane in Saltney (you outside Chester city centre). It has the electric steering column in if you want to have a look at it, it's exposed and everything.
"C20 LET bang"