Need Converted Van for Special Boy

Hi there, we are trying to save up for a converted van for our special needs son.  Rory has a chromosome imbalance that will leave him disabled for his entire life. He is bottle fed, cannot walk or talk, still wears a diaper and will be with us forever. None of that is bad news as he is the best thing that ever happened to us! He has taught us so much about humility, trust, unconditional love and patience that he has truly made our lives better and more enjoyable. We are a low income family of 5 and really need some help with buying a vehicle
that can handle rory and the rest of the family. We have saved almost $4000 but are still well off from the cost of even the cheapest suitable vans we have seen. Any help would be appreciated. Thanks for reading our story, and remember to smile!