Finding Empty Bins in the Warehouse through a custom search

I am trying to create a custom search to allow warehouse employees to be able to find empty bins upon item receipt.  Currently they have to walk around the warehouse to find an empty bin, write it down, then add it to the item record.   

I tried to create an "item" search, but this only shows bins with quantity of zero assigned to an item.  I want to see bins not assigned to an item with quantity of zero.

Let me know if anybody has any incite into setting this up.

thanks,

Derek