if you're planning on re-lacing the o.c.c. hoop with a disk brake ready hub, i'm pretty sure that any hub with the right number of spoke holes will work.
sometimes there will be different axle widths and diameters tho.
Your best bet in my opinion is to measure the width of the existing o.c.c. hub, axle width and axle diameter. Then try to find a hub with the same number of spoke holes, dimensions, axle width and diameter that has a disk brake flange machined into it.
I personally have never changed out a hub , laced a wheel or trued a wheel so i'm just guessing based on what i am thinking.
I'm thinking that the hardest part will be mouting the caliper bracket in the right position so that the caliper and brake pads line up with the disk correctly.