We have a lightly customized oscommerce site. We carry about 1600 products.
We'd like to have the function for customers to order an out of stock product by selecting a 'backorder' button that matches our design but that appears automatically when the quantity is 0. This could actually make the quantity less than 0 as long as the orders could still be made.
I would like a little highlighted note to appear that on their shopping cart page that says "this item is currently out of stock but will be shipped to you automatically once it becomes available". Something similar to the note you get when you try to order an out of stock item with that function turned off.
Then I would need some list or way to see what's on backorder and a way to process individual backorders.