Hi! I'm not an expert, but I've done a lot of research on this subject because of my own cats, one with kidney disease and one with diabetes. There are a few foods both of mine can eat.
There's a lot of debate about the low protein/low phosphorus issue for cats with kidney disease. I made the decision not to put my Gabby (She has Stage 1 kidney disease) on a low protein diet despite my vet's recommendation, because it's also been shown to cause muscle wasting in older cats. And Gabby HATED the food. I can tell you that after 6 months on a low phosphorus diet, the vet found no further loss in her kidney function. Low protein diets are usually recommended for late stage CRF cats. With Abby's diabetes, I would probably not put her on the high carb/low protein kidney diet, but instead try to limit her phosphorus.
The best food I could recommend for you would be Wellness Turkey. It's low in carbs and in phosphorus, and it's what I freeze and put in my autofeeders when I can't be around to make sure both cats eat their designated low phos, low carb diets. It also has high quality protein (no byproducts), which is easier on Gabby's kidneys. Petguard Chicken and Beef has no by products and low phosphorus, but is slightly higher in carbs than you should have for a diabetic cat (14%). But, it's just really important that the cat eats, so 14% isn't awful if she won't eat anything else.
There are also a few flavors of Friskies that are low carb/low phosphorus, but they contain byproducts. These are Special Diet Turkey and Giblets, Special Diet Beef & Chicken, Special Diet Salmon, and Special Diet Beef & Liver. I feed Gabby half the Friskies flavors, and half Petguard. She's not diabetic, but since the friskies are about 3-4% carbs, it averages out the Petguard, so she's still getting less than 10% carbs, and at least half of her food has no byproducts.
Again, these are just my recommendations, based on what worked for my cats. Good luck in finding a low phosphorus food that Abby likes!