I just had a new stereo stand fabricated by an off road truck builder I know. Welded steel. I bounced on top of it to verify it's rigidity. I plan to put my new (larger) amp on top. It is a tube amp and I want it to breathe. Instead of shelves, I use planks that cross under each set of feet. The amp is a tube amp and I want nothing above it.
Under the main amp I plan to put my center speaker and my power supply.
Under the left side (choke chassis) I plan to put my DAC. Under the right side, I plan to put my streamer. My external crossovers will be on the outboard ends.
Setting amps on the floor just makes them hard to deal with. Mine will weigh 150 lbs in 3 chasses.
Jerry