Make sure you get the wedge type, not the piston type. Phase II makes both styles. No brainer with both on sale for near the same price.
I don't have the G5960, but I do have the G0709 (14x40), and it has a BXA on it.
You could measure the cross slide to spindle centerline height, and than go to the Dorian or Aloris catalog. They have tables there with recommendations of tool post size vs critical height.