Not sure how rural of an area you are in. But I have seen the kitten formula at my local wal-mart. Hope that helps out
When I had my puppies and they need a little extra. I mixed up coffee creamer, rice cereal and little bit of warm water. You might try something along those lines. But I am not a vet, so take my advice with a grain of salt.
By the way, very cute kittens. Wish I lived closer and I would adopt one for sure :)