This is not going to be feasible with Digital File pro. With Digital File pro, you cannot select a folder to upload, for each image you wish to upload, you need to have a File form element, for each file form element, you need to have a Digital File upload instance.
Even if the File form field did allow for selecting multiple files at a time, the memory required for resizing a single would cause the PHP server to fail on resizing the volume of images you are proposing to upload at one time.
With DFP you will need to upload each image, one at a time.
