If you have a vet that doesn't want to be re-educated, or will not discuss options, then that is a very sad state of affairs. Here's hoping you can find a better vet. Given this age of the internet, there is absolutely no excuse for vets not to be educated on all feeding options. That being said, there are plenty of vets out there now who realise that there are significantly better alternatives to commercial dog food. Dogs do not have the digestive system to cope with grains.
Grains are one of the biggest sources of allergies in dogs.
My dogs have a diet that is high in protein, and low in carbohydrates - like nature intended. Talk to your local butcher, abbotoir, or chicken processor. Many of the leftovers that these guys consider waste, us BARF people consider fantastic for our dogs. Things like chicken carcasses, chicken necks, chicken feet, and chicken heads are considered rubbish, and are sold for next to nothing. You should be able to get these fairly easily.