Interesting! I think satin might be too shiny, also too floppy and I'm not sure would stand up to frequent washing. I think it would work for the side stripes though. I'd make them as a series of tubes with a small amount of stuffing in each tube. A firm cotton on the back would hold everything firm & prevent strain on the satin. I've seen iron-on plastic which might work to give shine, though would be sweaty I think. I wouldn't use chintz, it would lose its shine quickly with laundering & would need pressing. I think you need polyester, perhaps athletic fabric. Whether you can get the correct colour though....