I've very rarely seen them in LFS's, in fact the only times I've seen them I've bought them! Main issue with them is that unless you know specifically what they are and want them, they're pretty boring, and won't sell, for example the second time I saw them the same batch were there for several months after. And unfortunately I've only got two in my community tank, best thing to do would be to either look on aquarist classified for your area or perhaps ask your LFS if they can order any in for you? By the way I found mine in an Southern Aquatics down here in Dorset if that's any help.