Wheelchair Accessible Van

Hi, my name is Lainey. I am a single mother to 2 boy's. Robert is almost 5 and Landen is almost 4. Sometime during my pregnancy with Landen I contracted a virus called CMV. This virus is devastating to an unborn child and has in turn given him a life he will never be able to care for himself. Never be able to drive, go to normal school, bath himself etc.. Landen was born with Microcephaly and brain damage. As he got older he had many trips to the E.R. and hospital stays. His current list of diagnosis are cCMV, Cerebral Palsy, Epilepsy, Chronic Lung Disease, Pachygyria, and a few other issues. He cannot walk, sit, crawl, roll, or talk. He is wheelchair bound. I am his full time care giver. Aside from all of those struggles he is the happiest little boy in the world. He is getting older and a lot bigger. I'm 5'2 and it has reached a point that it is very difficult to transport him to and from his wheelchair. We received his wheelchair last year which has benefited him a lot, but he is very heavy and difficult to get in and out of the car. I have reached my limit on being able to carry him on my own. I am looking for some additional assistance so I can purchase a van to transport him. Having an accessible van would make our life much easier. So any help would be appreciated.
Thank You.