Begin in the plumbing section of a local hardware store. I used PVC fence posts which are expensive here. You could also order kits from China, but the shipping for a smallish system is outrageous, it's better for a large more commercial setup. There's other methods that I am going to try too which just involve buckets and aquarium air stones. The lights are from amazon or aliexpress.
RE: Tweaking my Hydroponics Salad Garden