Are cleats/brackets for attaching timber to brick available in different sizes
Sometimes there is no alternative to having something custom fabricated.  The fixing band you link to in your initial questions is not appropriate for this task and it is highly unlikely you are going to find "ready made cleats" that are manufactured for the particular packing you need to clear the coping.  Find a reputable metal welding/fabricator shop in your area and arrange to have them make the cleats you need.  Some small fabricator shops can be very reasonably priced.  1/8" (3mm) thick mild steel flat bar might be a good material, but it would need to be coated with a suitable exterior grade paint.   Alternatively, you could pay for more expensive aluminum or even stainless cleats to be made, depending on what the fabricator shop has on hand, your budget, and the aesthetic requirements.