I get asked questions about my aluminum stand. Here is information that may answer some questions:
My stand is made from 80/20 extruded aluminum (www dot 8020 dot net).
I used an 80/20 cad tool (runs on Windows, google "80/20 Frame Designer") to create the frame design and then reached out to 80/20. The 80/20 website has 'plugin' tools for Auto Cad as well. You could also reach out to 80/20 or an 80/20 distributor and work with them on the design.
I am not handy and wanted to make sure it all came together correctly so I used the Frame Designer cad program to create the frame design and then reached out to 80/20. They recommended using the 1530 extrusion in the stacked configuration (different than what I had used) and then put me in touch with a distributor in Southern California, Prime Resource. Oscar at Prime Resource was very helpful. He worked with my design to create the final version. He created a BOM that included cutting and drilling the stock, all of the anchor fasteners, etc.
I wanted flush mounted doors and panels and you can't flush mount with gussets. So instead of gussets holding my stand together, I am using anchor fasteners. These fasteners require counter sunk holes at the correct locations in the extrusion to hold the stand together.
If you are handy, have the tools and are comfortable working with aluminum stock, you can buy raw stock from 80/20 and cut it yourself and then use 80/20 gussets to put it together. This would save money.
My stand is 60"W x 36"T x 36"D. My stand, not including doors, panels and some miscellaneous hardware ran about $1200 IIRC. This included cutting and drilling as well as shipping. I had to assemble my stand because the dimensions precluded getting an assembled stand into the house. It took most of a day to assemble. I love my tank dimensions but assembling the stand was a PITA. Prime Resource will assemble and deliver the stand and IMO that is the way to go if you are using anchor fasteners and counter sunk holes.
Hope this helps.