Be honest with any breeders about your feeding plans. Don't want to make a bad name for snake owners. But I'm sure most rodent breeders are going to be realistic about using rodents as feeders. I wouldn't recommend gerbils though---you don't want to get her hooked on expensive and hard-to-find feeders! And $5 per feeder is pretty steep. Gerbils aren't much larger than mice; it would be better to switch to rats if possible. Use mouse bedding to scent the rats first for a better chance of acceptance.