Our new Pike's Peak Herp Society had a meeting the other day with a vet as a guest speaker who gave us a TON of great information on IBD. Here are some pertinent points he made that should help calm your fears and let you know that it's still ok to have boas.
1. IBD is not anywhere near as common as it sounds.
2. Adult boas can carry the virus for years without showing symptoms however...
3. Baby boas will crash just as fast as pythons if exposed
4. It does not appear to be airborn (but no one can say for certain)
So...if you want to keep both boas and pythons in your collection, you should try to just buy baby boas and strictly quarantine them. And never buy boas from questionable sources, especially adult ones.