Hello Flapjack. I have aphasia so I hope I have understood your comment correctly. What format was he thinking of that would suit him? Does he have any specific questions that we might be able to answer? Have you done keyword searches on Amazon? There are quite a quite a few hits on stroke and aphasia. Hope this helps.
I had one other idea. If your relative or anyone with him has a library card you can get the Libby app. That has a huge selection of titles both in book form or audible to listen to - all free! At libbyapp.com.