My suggestion would be to check out what kind of worms that are furnished with the kit as I have read some kits come with invasive worms.
Or you could make your own kit:
Get a book:
The Worm Book: The Complete Guide to Gardening and Composting with Worms by Loren Nancarrow, Janet Hogan
Plastic tub with lid.
Some sort of medium-like soil.
Go to the
local fishing supply store and get red wigglers or other suitable worms.