Hi kellycomposter,
If you're near anyone who has horse manure piles, there are thousands to be found there. Also, if you beef up your own compost pile outside with lots of kitchen scraps (vegetable peels and the like)and mix it with corregated carboard and garden refuse, you'll be amazed how many wrigglers you can find. You could then pick some out and add them to your worm composter. I'd send you some but the customs people seem to frown on exotic species crossing the border! (Did you know that the worms in our gardens in BC and as far down as the top of Oregon are imports from Europe. Only a few native species are found in isolated pockets not covered during the last glaciation, some 10, 000 years ago.)