The 747-400F and combi come standard with a weight and balance system. It is an option on PAX 747-400. There is also a dual system that can be purchased but to my knowledge only CargoLux has ever ordered it.
I think Airbus also has a system for a few of their birds.
The downside of them is that they can/will lie to you and is why they will never replace a loadmaster. Its just a last ditch insurance policy that you hope tells you the few times your airplane is terribly over weight or loaded wrong.
