yes! that's the kind of thing - Thanks!

I think the two motor arm idea would work very well - Also could look very nice/interesting. Also the entire arm could be positioned so that the view of the drawing area is clear.

Material wise, I will be looking at using brass (or aluminium) with wood for a kind of retro/steampunk look. Would be great to use something like servos but not sure they would be up to the job? Maybe small steppers might be better.....?