The ZenCart Quote Payment Module is a clone of the check/money order module, which is provided to allow customers in a store to check out with a no obligation quote. And it works great with two other mods: Catalog Invoice and Order Copy.
Catalog Invoice allows your customers to create their own printable invoices. These invoices look just like the ones you can produce in Admin->Customers->Orders->Invoice.
Order Copy allows your customers to easily convert past quotes into orders by adding all the items from the quote (along with their attribute settings) to the cart, for checkout and payment.