I think the industry has gone to foot control because it is generally safer and easier to use. Is there any way you can adjust the pedal height or seat position/height to make him more comfortable on his current machine? If you can figure out what the specific problem is, pedals too hard to push, too far, lack of strength or flexibility to push them etc, you can maybe fix the issue or find another foot controlled machine that will work. Hand controls opens up another bunch or safety issues. The biggest one for me is that some of them just keep on going if you remove your hand from the control, where a foot control will return to neutral and stop. I have this setup on a JD314 and 317 and much prefer foot controls.
I agree and speaking as someone who once swore he would never own another hydro, I have grown to like them and especially the foot control. I need to take some time and get more in depth with him on this subject. He knows what he is feeling when he is mowing. We discussed some sort of a seat belt but we'll just have to hash this out to see what the real problem is. This has been a very good, reliable machine for a cheapy. I recommend them for someone who just wants a mower. I would hate to see him get into something that wouldn't hold up. The way he's going he could be mowing for another 5 to 10 years!