iron sources

24gauge will be light, but also a bit floppy if it's 1" wide.
I doubt you'll find this off the shelf, but a HVAC or box-making shop with a press brake should be able to bend some up for you.

I doubt you will find that size angle in the normal hot rolled products. I have some 1/2" x1/2" x 1/8" angle, was MUCH more expensive per pound than the larger sizes.
Plan on getting some formed angle. It is available as either roll formed in large quanties and limited sizes or brake formed in 10' lengths and infinite sizes. Any HVAC or ornamental (copper) roofing suppler can fix you up.
Steve B wrote:

Be sure to make a drawing of exactly what you want, complete with dimensions and any holes you want punched. That way the guys at the sheet metal shop will know for sure what you want.
Paul

I doubt you can find 24 ga steel angle and channel. As mentioned by others, you can have it made by a sheet metal shop- they can shear strips, then bend them in a brake.
In aluminum, there is a line of small angle and channel available- not 24 ga, but some of it is available in 16ga. It comes in 12 foot lengths, preanodized. It is used as trim by carpet, flooring, and cabinet installers, and is often stocked at big wholesale flooring companies. Made by Futura. You can download the catalogs here. But you cant spot weld aluminum, at least without a very expensive and specialised spot welder. Pop rivets will work, or self tapping screws.