If you cannot afford to pay for a SD (Service Dog)... and I don't think many people can... training yourself may be the only option. I do know that some people do fund raisers to get the money for a SD. I have attended several of them. One lady is a student at our local university. She has a friend that has organized car washes, bake sales, dog washes at at a local pet store for example. Often, if you belong to a church, that is a way to raise money.

True that the dog can't count in your # of animals - but it has to be a service dog, not in training.

I am not sure what tasks you would need, but even though 10 is old for a SD, old dogs CAN learn. You could teach your dogs you have now to pick up things for you, close drawers etc (depending on their size). It would give you some help, plus some experience training.

Have you actually contacted the service dog organization in person to verify that they won't place dogs into homes with other pets? I ask, because many of the people on the service dog forums have multiple dogs, and they have program trained SD.

I'll PM a couple forums to you - if you join there, you might be able to get some more suggestions. There are many SD trainers on the forums, from all over the country.