I think you need to use the type of insulin your veterinarian feels most comfortable working with. Maybe you will be able to get your cat off insulin anyway with a little time. In the cat there are factors that help them to respond well to therapy. It is important to feed wet cat food and no dry food at all if possible. All foods, including treats, should consist of ingredients suitable for a diabetic. In addition I give Dia-IonX, digestive enzymes, probiotics, and fish oil. Dia-IonX helps the body to better utilize the diet and supplements for a synergistic effect for faster healing. It is also important to avoid giving water that contains chlorine and fluoride.
Exercise helps to move glucose from the blood stream into the muscles helping to regulate the blood sugar levels. Hopefully you can get your cat to play. Having a consistent schedule is necessary in good regulation.
Please let us know if you have any other questions.