+1 on doing a search on this site for 80/20 stands. Not trying to be cute about it, but there really is a lot of useful info about how best to design a stand, etc. What size tank are you going to support? I ask because this stuff gets expensive fast, and for larger tanks you will need heavier extrusions, and more parts. I've only built support structures for my lights out of this stuff, and have easily spent way more money than I thought it would take. I like the look in certain applications though, so it was worth the cost - to me.
As far as ordering goes, it is pretty straightforward. The hard part is in designing a stand that will be safe, making sure to include all of the connectors, braces, etc you need. That's where looking through other threads will come in handy. Once you have a design and an idea of the parts you need, look for better prices on ebay (8020 has a discount store on ebay). You may be able to buy a lot of what you need in discounted bundles. You'll also find knock-off 8020 stuff on ebay, at least for hardware, and I have also used that without a problem.
