I'm starting this thread as a place to assemble knowledge of killer yeast strains.
"Killer yeast strains secrete protein toxins that are lethal to non-killer strains, and other types of killer strains belonging to the same yeast species. They also can kill other yeast species [1,2]. Each killer yeast is immune to its own toxin and also to the toxins produced by other yeast strains with the same type of killer phenotype . "
So far it seems Lalvin K1-V116 is readily available at most suppliers.
There is an interesting thread here...
According Milk the Funk no killer strains kill Brett.