I don't know what happens when you put N/A under the physician's name, but I've simply put down "Walk-in Clinic" or "Emergency Room" before and had no trouble receiving my medication from NROPs. Wish i'd seen this sooner to throw that idea to you. Hope all goes well.

Edited to add: As far as the money order goes, if you know what the total is you can go ahead and purchase it, but leave the "Pay to" area blank. That way if your order doesn't show up, you can go back to where you purchased the money order and write it to them to get your money back (make SURE you get a receipt when you BUY the money order)or you can make it out to yourself and deposit it in your bank account. Hope that helps.