I'm looking at the Polaris Ace models. 60" wheelbase, single seat, fits in a regular pickup bed, and has a full rollcage.
I've been thinking of buying one of those for the Ranch just for patrolling the fence lines on the big Hill Country ranch I manage.
Took one for a test drive at the Dealer's the other day, and it rides smoother than our big double seater Ranger 900.