So, I've decided to design a mounting bracket for a 1000W ballast I ordered for my Kim EKG. What advice do you guys have? What material and thickness should I should use? Currently, I am set on using 1/8 inch (3.175mm) 5052 aluminum.

By "mounting bracket" what do you mean exactly? Do you mean just some pieces of metal to secure the ballast to something? Or something more complicated

I hope these images help explain what I mean.

Ahh I see. So essentially a big plate to mount things on. I think 1/8" aluminum should do just fine, but it might be cheaper to use thinner steel. Are you making it yourself or having it made for you by a service?

I am having it made by a service. I would prefer to use thinner steel since it's cheaper, but it rusts, which is a big no for me.

Oh I see, that makes sense. I think this is a pretty good plan.

Zinc plated steel won't rust, and won't cause galvanic corrosion of the ballast where they come in contact with each other. But is more likely to hum when powered up (probably very soft and quiet hum for a thick plate)

If the environment this is used in is likely to corrode anything, i would be concerned for the ballast itself