Ekar and ultra torque use the same fiddly bits - wavy washer, circlip and retaining clip according to campag parts listings, which implies that the bearing inner and outer diameters match. The ultra torque and ekar design is basically the same, but all "official" sources say the bits are different.
Ekar have stainless bearings, new part number (these fall between the steel parts and the high series ceramic parts) - is that the only difference or have they mucked about with the outboard seal surfaces as well?