Common manufactory would like use Aluminum pipe rather than steel stainless pipe, cost is a big reason. I agree your point, because machining Aluminium pipe will easier than steel stainless so much. Could you please let me know how to contact with George Dyson? I want to know more about Aluminum pipe, though I would not use it to my products. Using Fiberglass tubes is good idea, I had ever think use carbon tubes. It's very lighter, but it's cost will very high. I'm worry about it's has too much flexibility. And, that will make price higher more. To me, as a new manufacturer, I do not want to sell higher price products when I just appear in the market. I don't think using PVC pipe to build one is a good idea, because once PVC pipe be beared, distortion will happen, and it's specific gravity is very big.