Like Frost said, for about 400 bucks, you could have a molded hem.
Or you could go the pep way and get a decent one with around...100 bucks.
That's about 20 for resin, 40 for the visor, 5 for the card stock, and 15 for bondo and 20 for misc stuff like paints/glue gun/glue. That of course is only if you got a respirator and sander.
Or cardboard. I've seen great looking cardboard armor for only 50 bucks.
And i'd check your sig size...it looks a bit big.