my uncle recently got one of these installed into a hill climb mini, it has a Honda motor and front control arms and such, and then like 9inch slicks .... it was a right pig to drive before the electric steering, now its like its on ice its that light
it has a dial on the dash to allow them to dial in how light it is, from what I can see just looks like a potentiometer to adjust it. they did say that if they have speedo into it they could have speed sensitivity, but for their needs not worth the effort, they just adjust the dial to suit tight tracks or faster bigger tracks and that's it ....
I don't really know the requirements of them electrically but from what I've seen they don't use massive power wires or anything so can't be too much.
My holden cruze has electric steering, its awesome, light as a feather in carparks then goes heavier on the freeway etc to slow down twitchiness! .... I was a bit apprehensive when I first heard of electric power steering, but after 70,000kms I've got nothing negative to say about it.