Want to make a Gen slide - how thick of Alum plate?

I just redid mine last week after almost 7 years use
I used new 5/8 plywood, placed a piece of 1/2 angle iron across the front each between the two slides, to aid in preventing any bowing of the wood
And a section of Gray colored floor fatigue mat on top of the wood
It aids in preventing generator 'walking' during heavy load start up, and vibration damping, if you want to use Alu plate, i would put wood on top
Better softer sounds damping, vibration etc..