i,ve used steel pins to hold gate nets up and 8 inch ones to secure net , alan salmon has lovely lightweight ones on his longnets with rubber handles , wood is the norm on ferret nets , although you can use what you like best , fibre glass is good on longnets also .
cant speak for long nets but when buying ferret nets instead of using traditional wooden stakes, i use tent stakes, cost about 20p each last just as long and are a dam site easier to put in to the ground