I've not heard of anyone actually doing it but there was talk about fitting the electric power steering from a Corsa or similar. This means cutting the column to insert the gearing so I would only trust that to an expert welder myself. Saying that it's a common mod on VW's so it can be done.
I actually find the normal steering OK, a little bit heavy at parking speeds but surprisingly light on the move. A lot depends on the wheels and tyres I've got pretty standard width rubber inflated to 45 psi and it's fine.