Raven,
Kezygirl is right, you can use a 901 atomizer on a VK battery without modification, but not the other way around.
Steve is the owner of V4L and his goal is to treat everybody the way he wants to be treated himself. Everyone is given the benefit of the doubt and presumed honest unless proven otherwize.
I highly recommend the Vapor King from V4L (as if you couldn't tell). At least get yourself a box or two of the cartomizers and check the whole thing out yourself.