Instead of products saying "Sold Out" i want it to say "On Backorder"

Hello Team, 

Is Backordering an option? I need this to be an option because some items we sell are just too big or expensive to just sit in our W/H. I need a "On backorder" button  when the customer pays for the goods and then it gets delivered at a later time separate from the rest of their order.  This also assists with cashflow as we sell 1000s of items.