build you own........

[flyerncle]

They are dirt cheap at Machine Mart these days and no hassle regarding strength of welds and weight capacity etc.

[mr henderson]

Steel and labour is so cheap in China that the items you mention simply aren't worth building, to build them to a satisfactory quality would almost certainly be more expensive than buying (except for the trolley, as I don't know if anybody sells a ready made one)

[AshG]

as everyone else says you can buy proper ones from machine mart for less than the steel would cost to make one.