Have you been searching the thrift stores? It might be pretty easy to sew, and im not a seamstress. Sometimes you can find the body of the garment at goodwill, then make the hood or take from another costume.
my husband bought me this one a couple years ago. its long and the hood is huge, can hardly wear it over my head if i want to be able to see. made from some sort of crushed velvet feeling material (probably synthetic, i dont know i havent looked at the tag) and closes at the neck with a decorative velcro piece. it keeps me relatively warm but its not super heavy either.