my buddy was a skilled welder in my town,he built me a pair of squat racks similar to the ones in the pic u posted.he used truck rimes with iron steel posts,he said they would b able to withstand 3500lbs
i told him thank u but i dont think we will ever get to test that claim
he also built me a support steel rack so if i couldnt get the weight up i would be able to just let the weight go down and the racks will catch them,kinda like the pins on the power rack but he made it in a rack type of thing. i would just position the 2 racks on each side of me before i started squatting and then id go up and down in between them,if i ever got stuck id just go down and the racks would catch the weight and i would just crawl out between the racks