Curious, when you build the stands are you able to perform a stress analysis for the weight that they will be holding.
For instance, I use solidworks, and I'm able to input the FEA data for the material used and then be able to see the weak points and build them up.
I recently did thos for a local on a large 600g tank and was able to design a stand that will easily hold the weight.
I fear that without proper calculations these stands aren't going to be up to the task.
At the very least it will help determine what extruded aluminum profile will be the best choice for cost and strength.