I have a pair and if time permits I'll take a look and see what bearing number(s) they use. But I have to mention that whatever they are if you want to retain the "grease guard" function you will want to source bearings with just one seal and install them so that seal is facing out from the center of the axle.
You pump grease into the hollow axle at the exposed (inner) end and it pushes through the open side of the bearings (both inboard and outboard) and flushes the old contaminated grease out through the sealed side.
At least that's how I remember it was supposed to work.