There's not much that I can add to the previous answers except this:
Don't be afraid to be creative (with your attorney's supervision, of course). Consider asking for a portion of your rent to accrue towards your hand money deposit. You may also ask for pre-posession, meaning that the closing is set for 6-months away, but you will pay into the hand money escrow in monthly contributions, perhaps referred to as "rent".
Remember, a contract is valid as long as both parties agree to it... just make sure your attorney supports your half of the bargain.