I don't know but will try to do some research as I do have some experience adapting for handicapped. Is he in a wheelchair or is he able to get around himself.
Using the tripod is good and don't forget that he can put the camera on delay so pushing the shutter doesn't wobble things.
I'd also look for a remote shutter release; I have an rc one and also look for a camera with a live view lcd, preferably one with a tilt/swivel screen.
Are you looking for dslr or point and shoot?