witch idea will work the best to hanging a light in my flat pan patio cover made of aluminum alloy they add a texture to it to resemble wood?

so it not smooth because of the texture that on it. want to hang a shop light LED it has a chain on each side to hang it from.

and so here we go 

idea 1. 

a strong magnet on the roof that has 600 of pull force aka can left 600 lbs. then put      a smaller magnet that can barely pull about 20 lbs off the ground. then put that on        the ceiling to connect to the other magnet it's like sandwiching aluminum alloy to a      super strong magnet and to a smaller magnet or like a Oreo cookie the top                  chocolate cookie part is the strong magnet and the white part is the aluminum              alloy and the bottom chocolate cookie part is the smaller magnet my photo show        also what i mean? 

idea 2.   

put on the roof a steel flat bar of 1/4 inch thick then on the ceiling a fishing                  magnet of  600 pull force aka can left up to 600 lbs. 

this idea i'm not  sure if it will work because of the aluminum alloy is in the way of making a directed contact to the steel flat bar also the bar will not be to wide and the fishing magnet is a bigger width then the flat steel bar so it not getting all the pull force the reason why the bar can not be wider is because the roof as 2 tiny  pumps and if i was to put a bar that was full width it would have a gap and not be flat on the aluminum so the magnet would have less attraction to the bar