Tell us the deadline first

Requirements usually treat availability as a property of a part: either it can be had or it cannot. In practice it is a property of a part, a quantity, a supplier and a date, and the date is the one most often left out.

That omission has a specific cost. With no date, we quote the best configuration available. With a date, we quote the best configuration that will actually arrive in time. Those are often different, and the second is the one your project needs.

The same goes for splitting an order. A requirement that has to land complete is a harder problem than one that can come in two deliveries, and if a partial delivery would unblock the work, saying so widens what we can offer you.

So: the date, whether it is firm, and whether the order can be split. Three sentences at the top of a requirement remove a round trip that otherwise happens after the quote, when there is far less room to act on it.