Go with one of the classics, because they're used for a reason. If you sound too stiff and formal, it comes off like a holiday card. If you reiterate your call to action, it can carry a whiff of desperation. Just get out gracefully and quickly once you've said your piece.
Here are some other terms that may also be included: Confidentiality » the agreement and any information learned will remain confidential. Covenants » things each party must do while negotiations are taking place. Special Terms » any special terms that the parties agree will be in the purchase agreement, such as leaving certain items of furniture or hiring certain employees.