Deal Due Date listed in Board View

Our company really focuses on when a proposal is due to the client. Is there any way we could customize the date on the deals to a customized property instead of the default property of Close Date? Close date for us represents if a proposal has been awarded or lost - some in which we typically don't have hard due dates for. 


This would be extremely helpful for us to prioritize our proposals based on due dates rather than hypothetical close dates.