I do theatrical lighting, I don't know what regs are like over there, but a licenced theatre here has a lot of regulations and official inspections so would not allow you to use a home-made rig like that for a public show, and any electrical outlets on or in front of the stage are under the control of the lighting operator.
If I was building one to use at home I would probably use domestic dimmers rated for halogen lamps (and we use a different kind of plug for switched and controlled circuits to lamps). And probably a separate 2-pole switch and dimmer for each lamp or smoke machine, with a main switch and RCD for the whole lighting board.
I do not think you would economically be able to buy or assemble a professional mobile rig as they use SELV or digital controls at the operators box to (usually) 3 phase lighting packs in the lighting gantry, then flexible cord extensions to the lamps and other devices.