PAM is a must. Check any local reptile shops, one near me carries it, and that way it's cheaper and faster than ordering online. I've also seen it at Petsmart. Wherever you get it from, get a few cans, because you're going to need to treat your entire collection as well as your new additions if they've been in the same room.
This is going to be a really frustrating few months for you if you decide to keep these guys. It might be better for your sanity (not to mention your wallet and the health of your other animals) to return them and get snakes from someone less shady.