Hmm....like the old Snapper/Country Clipper zero turns with the joystick control. It actually is pretty intuitive once you get the hang of it. Only problem is, you would have to take it all the way to Tazewell for service. That's the big downside to buying factory-direct.
If he decides to go with a zero turn lawn mower, look at the Bad Boy or something with an electric or hydraulic deck lift. Most ZTRs require a right foot to raise the deck, with the exception of Bobcat, which has a left-hand foot assist.
For the cost of an ASV and the attachments, you could get a tractor, ZTR, and a few attachments and accessories and still have a few $K in your pocket. Skid steers are amazing tools, but most landowners don't really have enough of an application for them.