If you have AP holders, you will probably be better off doing an AP room-only discount (which you can add the dining plan to)
Those AP discounts are the best discounts, if you can get them for your resort and your dates. You can't add a dining plan to an AP room-only discount, but you can have them "convert" your room-only to an AP ticketless package (same process as non-AP conversion...book new package with same room type and rate, and then once it is confirmed cancel the Room Only and refund the Room Only funds.) What's the difference between adding and converting? Oh, about 30 minutes on the phone with Disney.
