Though they are not cheap, Carolina Biologicals is good to deal with. They replace anything that does not arrive in good shape, and are very prompt to respond to questions or complaints. I have purchased algae cultures, moina, daphnia eggs, dero worms, wingless fruit flies and a number of other items from then and they've always been good. You get culture information with them too.
Only drawback is that because they mainly supply academic institutions, the portions of some of the live cultures may be rather small. But they are pure and uncontaminated, and they do back up their goods. Ship almost anywhere at all.