Petco carries both NLS and Omega One. Petsmart only carries Omega One.
As for the freeze-dried bloodworms, I looked at the container, and the only ingredient is "freeze-dried bloodworms." So when you go to the petstore, look at the container. If they all say that this is the only ingredient, then it shouldn't really matter what brand you get.
(Three of my guys will not touch the bloodworms, but my newest keeps refusing pellets. I finally dropped a bloodworm in there today, and he attacked it. It could be that this is what he was fed previously, so he's used to it....)