If you do this, make sure you buy birds from a hatchery that immunizes with all three types of vaccine. Unless you can find a breeder who has had all of the testing done to prove type B blood type, you can't be sure you will not see this again.
When you have time and can things slow down enough for you to breathe again, can you elaborate on this? I hadn't heard about it before and I try to keep on top of new Marek's research!