How do I set up Market Press so that payment is not necessary for shopping cart items to be sent?

The store is for an Optometrist who wants patients to be able to look at eyeglass frames ahead of their appointment and put a few they like in the shopping cart and send to him, so that he can make sure he has those frames ready to show the patient when they come in for the appointment. Therefore, no payment should be required online, as payment will be made during the visit, once a single eyeglass frame is decided upon.

Please provide specific detailed explanation of where I go to do this and exactly what I need to do. Thank you.