balance and rest

Which one is correct?
Term of payment: 50% in advance and the balance at delivery time
Term of payment: 50% in advance and the rest at delivery time

I'd go with the first. But, since this pertains to receipt of cash, I'd be very specific in order to avoid any confusion whatsoever:

Terms: A down payment of 50% is due in advance. Balance due upon delivery of merchandise.

Both are correct but the first is what you'd see written in a contract, the second is more casual. Elaine's suggestion is okay but why jump on the band waggon of making incomplete sentences in some ugly attempt to sound more "bussinessy"? Why not the following?

Terms of payment:

A down payment of fifty percent is due in advance. The balance is due upon delivery of the merchandise.