Large dog containment situation

I searched through dog fencing posts first but can't find what I need, I'm hoping someone can help. I'm trying to help someone else keep large dogs in the garden, they are constantly breaking out and "visiting" neighbours. I don't want to go into detail but I lost a pet to these dogs the other day and can't face losing more, the owner wants a solution but doesn't know what to do next. I haven't been in his place but he says he has a high fence and they can still climb over it. I was advised to try metal fencing where the top seems to "fold" over inwards preventing the opportunity to climb further and escape. I know they are mostly for security/home protection but I think they might also need more exercise, unfortunately I believe the owners are physically unable to control them but I may be wrong. I saw videos before of overhead leads that stretch strong cable elevated across the garden allowing the dogs to be hooked but free to walk about in the garden without escaping. These are very big strong dogs, larger than shepherds and almost as big as wolfhounds but heavier. Does anyone know of suppliers in Ireland who might sell these kinds of dog items, from my point of view, this is rather urgent. Any help, advice or suggestions would be a godsend and in case it doesn't make sense, if I help him deal with it, all of us as neighbours and our pets will be much safer. Many thanks and Happy New Year.