I got my cultures from a seller called kwaquatics on aquabid (look under the live foods section). She's a great seller and her cultures are AWESOME.. very healthy.
She often does choose 3 or something like that and I would advise that you buy one of those auctions and get microworms, bannana worms, and walter worms. They're all roughly the same size but have different nutrition so if you feed all three at once you cover more of your bases.
Vinegar eels are also a personal favorite of mine. I have some I could send you for free (as long as you cover shipping) but I have some concerns about shipping with it being so cold. The last cultures I sent out arrived safely though.