14ft???
The best approach is to treat it like any other larger tree you'd buy from a nursery.
This means you need to tie up all branches as much as possible, kinda like many Christmas tree farms do. You can use vinil-coated steel wire since it's the least likely to injure the branches.
Also since I don't know what weather you'll be dealing with it may be wise to wrap the tree in old blankets and the like: remember weeping figs don't like temperatures under 50F. You can wrap the vase in plastic sheets: they will also double as packing.
Finally: if you don't have it already, rent a larger truck, van or trailer and borrow tie-down racks and bungee cords. Transporting such a large indoor tropical on the roof of a car is not recommended.
