I would stick with a 3/4 wheel electric. They are actually more stable than a 4 wheel truck. Most current production 3 wheelers have no issues with ramps. My recommendation is going with a 48 volt and getting the largest battery that will fit in the compartment. Some sales people will tell you that a 36 volt battery and charger is less expensive than 48 volt but that is not true. If you price out the largest 36 volt battery with a 3 phase matching charger the price is the same as the largest 48 volt package.
I like the Linde truck. It is extremely dependable, compact and stable. Get a demo and see what you think-but make sure it is 48 volt.