I got the Vinyl from PartsExpress.com. It's pretty cheap, like $10 for much more than I needed. It's good stuff and adheres well.
As far as making them to sell, I'd love to but with the current equipment I have it takes far too many man hours to be feesible. I really don't have the right equipment set up right now or the space but I will have a garage built next year I hope.
I'd love to start a small side line buisness making truck accessories, maybe, someday ... .