Stand up vs sit down should be determined by the intended useage. Each has an advantage in their own way.
The stand up would have a tighter turning radius & easier operator mount/dismount.
The sit down has the availability of higher capacities & has a lower center of gravity-therefore is better suited for ramps, inclines, etc.
As far as batteries, both types should be able to operate thru an 8 hr shift without a recharge.