I don't know if you already have this issue sorted out, but I've complied a little list of all the pirate-ish patterns out there.
I suggest going to Joann's when they are having a pattern sale, you'll save tons of money if you buy them at this time. Good luck with your Cosplay! It sounds awesome! I'm cosplaying pirate Iggy(the normal one) and I used simplicity 4923.
Someday, I'm gonna be super awesome!!! -Vaati the Picori
Maiko Hikizuri- 5%
Erik/Phantom of the opera commission-10%