I have the electrified poultry netting from Premier. I bought it because like you, I have problems with the area foxes. The netting works. I can let my birds out all day with no problem. I've seen and heard the foxes, they are still around, but the chickens are safe. When a fox, or other animal approaches the fence, they always lead with their nose to check things out. A shock, in excess of 7000V to the nose, sends an instant message to get far away. They don't even think about climbing it or coming near it again.
Jack