I would recommend speaking with a loan officer, your lender or Jeff Belonger will be able to guide you in the right direction. He's in New Jersey too. You can find him here on Trulia or http://activerain.com/jeffmortgageman.
With that being said, lets say the seller accepts the earnest deposit and agrees to wait for the balance of your down payment until closing, what if you don't have the money in time for closing? Is the seller willing to take the risk that you'll have it by closing? Or will they take the risk and take their house off the market based simply on an earnest deposit? For my sellers, I always negotiate a higher second payment which is due 10 days after attorney review to prove true motivation.
Again, try contacting Jeff Belonger and tell him your situation. He'll guide you in the right direction. I honestly think this is a question best answered by a loan officer/mortgage rep.
Gina Chirico, Sales Associate
973-575-6353 ext 17