I am tring to decide between Ball Screw or Rack and Pinion for the Drives on a 6' X 4' CNC router table.

Accuracy as well as cost is important!

Rack and Pinion seems to be a cheeper option but accuracy is lacking. I have thought of using a 20mm Rolled Screw fixed at either end and then rotating the nut to provide the motion. Thus whip should not be a problem.

Is this a sound approach to this problem?