Looks like you put the cart before the horse on this one. I'm sure you negotiated a deposit when you made the offer, whatever it was you will have to put it down yourself. The other problem is that you most likely will not be able to assign this being a bank owned property. What you will need to do is a double close.
The BIGGEST thing here is that you don't have a buyer. That's wholesaling 101.....have a buyer's list before you have a property tied up....or at the very least, have a plan BEFORE you get the property. If I were you, before you put your deposit down, I would ...1. Back out of the deal 2. read, read, read this forum and learn wholesaling. 3. Find someone who can possibly partner with you 4. Keep reading 5. maybe find a FSBO and do an option agreement ( if you don't know what that means...read, read, read ;)
Hope that helps..........