A long winter coat, like below-the-butt long. You could wear a duster, too. I know those are just coats, but can you even buy cloaks nowadays?

Nevermind, I see there are cloaks for sale, some of them look pretty cool and they're not too expensive. I say go for it, and you can always make your own with fabric, thread, and a broach if you think a custom-made cloak suits you best.