Hard to tell from your pictures but you want the center line riser, Taig will
Know what that is, it is not listed on the parts page and I forgot
What part number it is actually called.
Silvia
The pictures you have here are both same height risers, the only difference is one is a straight (centered) riser, and the other is an offset riser, which is a standard Taig item, when used on a headstock it gives you a larger turning radius. The straight risers are usually made for Hightower, myself and Todd
Either way, since you are using it on the tailstock it should be fine.
Regards