Woerman, camping at St Lucia is also good, but dont think you have such easy access to the beach and good spots like you do at Vidal.
Suppose it will also depend what time of the year you would like to go, but if it is in summer I would opt for Vidal.
Camping/caravan sites are good, electricity, clean ablution facilities (perhaps avoid very busy times), conveniense store, and St Lucia is only a 30 minutes scenic drive away for replenishments.
I felt much safer camping and fishing at Vidal than most other venues, including Kosi, Sodwana, Tugela.
Sodwana is also an option and offers good fishing in front of Mseni Lodge, but walking back to the camp over the dune is a major schlep and I dont think good for us "senior citizens". Dont know how fit your dad is.
The monkeys at Vidal are just a serious problem - much worse than Sodwana. Forget a "Cattie" and take with a seriously pumped-up paintball gun.
Hopefully I will be back at Vidal early in the new year.