Hi-Health here (biobest now). Started off as Orkney Livestock Association a few moons ago to make Orkney BVD free.
Talk to both as they both differ in how they test and interpret results, a classic example is that a vet took blood samples from an animal and sent it to both sac and bio best and the results were completely different. I've heard many stories of people changing from one scheme to the other as results are not as harsh, shouldn't be that way but it is.
That's probably why they chose to eradicate bvd & not johnes!BVD, although horrible if it gets into a naive herd can be gotten on top of fairly easily, it's Johnes that is the massive up hill struggle if it settles into a herd.