Basically, anything pure protein is a good treat for a diabetic cat. Freeze dried or cooked or raw chicken would all work well. Mine love the Halo Liv-a-little freeze dried chicken (also great to crumble on food to get a picky kitty to eat), the Pure Bites freeze dried chicken, rotisserie chicken from the grocery store, things like that.
No, the Temptations have a lot of corn so that makes them too high in carbs for a diabetic cat.