I'm actually headed out right now to pick up a hoodie or two for a Jack Frost cosplay. Kohls has the perfect style on sale for like... $15 on their website. I think it's the men's Tek Gear one if I remember correctly.
If painting the frost on it turns out well, I might make extras for my artist alley table down at Katsucon.
Katsucon ~ Zenkaikon ~ Otakon