[AlecMataloni]

Although 1/8" material is pretty hefty, you're missing an opportunity to add essentially "free" stiffness to your frame members by only using L shaped metal pieces instead of "C" shapes.

I would recommend that you add a continuous bottom flange to every piece of sheet you have in this photo.

Also, if you do what I mentioned above, you could certainly use a thinner gauge of metal (like .090"), which would allow you to have less lightening holes. Your turret punch sponsor will thank you.