I used to own an RZ67 that I purchased used. It came with both the waist level finder and an AE finder. I hated the AE finder because of the weight of it. It makes an all ready heavy camera heavier.
Of course that is my opinion and to be honest I prefer waist level finders anyway. Some people love the prism finders.
I do recommend that if possible try it on your RZ before you buy to see if you don't mind the weight and bulk.