I had some https://www.8020.net/ from a different project. I decided to turn it into an entertainment center of sorts. I got custom maple boards made to fit into it.
It is extremely solid! I'm using a 40mm solid extrusion, so it is also pretty heavy. Because it is aluminum, it is not as heavy as it could be i guess.
It is expensive, but the place where they really get you is in all the fasteners. I just had a bunch of stuff left over from something else, and I didnt want it to go to waste. Therefore, I build audio stuff, haha!
That is an interesting point. I just sit on the floor in front of the center to swap out the records. I could swap the record player and the phono amp with the headphones and headphone amp if I find out that it bugs me.
Another fun thing about 80/20 is that it has cable tie mounting blocks https://8020.net/shop/12316.html to help keep your cables under wraps.