I used stainless because it was available, and because of its tensile strength. Heavy gauge aluminun would work very well. Something like .040 or .060. You can often get scraps of this, with a baked on enamel color coating, from local sign shops. Many times they also have the bender/break sheer to fabricate it, too. I used a small bench-top bender for mine.
Believe me, you will want something that's very stable. Video quality suffers tremendously with a shaky camera. I can tell a big difference when I turn off the Electronic Image Stabilization feature on my camera.