I've been buying things like this from a restaurant supply store. All of my crappy sheet pans that would warp and buckle in the oven have been replaced with professional grade half sheet pans and I'll never look back.
After stumbling onto a video on the topic, I decided to pickup 3 half sheets and it has been a game changer. Biscuits have a perfectly golden brown crust. The ability for these things to distribute heat evenly is awesome.
Most professional baking pans are either aluminum or aluminized steel. Stainless steel pans are sometimes used, but food sticks to them like you wouldn't believe. Silicon mats, acetate sheets and parchment, are usually used to line the pan anyways to further prevent sticking.
The standard is an aluminum "sheet pan." They're widely available on amazon, in big box stores (my local Target carries them), and in restaurant supply stores.
A typical home oven can fit a "half sheet."
I've got "nordic ware" brand half sheets from Target, I think I paid $9 each? I'm very happy with them.
You can also get quarter and eighth sheets, which are nice for toasting things in.
Use parchment paper or silpat mats on them if you want them to be nonstick.
North America's largest manufacturer of commercial bakeware. The standard material used in the commercial baking industry is Aluminized Steel. There is no subustitute. Aluminized steel is a steel substrate (steel is the best most even heat conductor) covered by aluminum.