I've got multiple cages and have used both netting and plastic fencing. If I was wanting a short term cage like you mentioned, I'd stick with the plastic fencing if you can find it with an 1/8" mesh. Regular twine netting is great, but it's far more expensive than the plastic fencing, takes larger PVC pipes to support the added weight, and is a bear to deal with once it gets wet.
Depending on the volume of fish you're wanting to grow out, a floating holding box may also fit your needs.
