Prob not a true "C" channel but the dimensions are 12" tall X 8" deep, 132" long, plus another smaller one at ~107" long 12" tall with 4" flanges. Not to mention a couple of other smaller bits/pieces. I only have a 10' 16 ga brake and won't even attempt .125" metal on it.
I just found someone local with a 12' press brake, but he can't do it that deep so I might just go with two angles, weld or glue them together and simulate a full channel. It's just a decorative item so I'm not worried about it supporting anything. I'd still prefer a one piece unit (simplified installation, etc) but will make do.