I was thinking to use those Norton, white wheels, 6 or 8 inches diameter in 2 widths.

Rotating around the Y axis as per industry standard Jones and Shipman 540. 2800rpm.

That wheel overhang detemines the useable Y travel. I can have up to 300mm, less the wheel width, but I don't think I am quite that brave. OTOH, the more it sticks out the greater the stiffening torque on those linear bearings.