The 80/20 product is a great one. Sound and Strong enough to even hold large tanks (with the proper bracing that can also be supplied from the company). If you download their program, you can design and setup variables to find information about support strength, deflection, etc, and recommended build setup.
I first found out about this product searching the web. I was looking to hang a 40lb fixture. Using their program, I found that I would only need 1" tubing and brackets. This is some strong stuff