Is there a preferred guitar pick size to play "Your Guardian Angel" by red jumpsuit apparatus?

I was just learning how to play your guardian angel by red jumpsuit apparatus and i knew that different pick sizes make slightly different sounds. When I play this song (which is in drop c tuning by the way), I was hoping for exact likeness. Is there any pick size that would get me as close as possible to the song? Also, my guitar has some rattling going on when i play notes toward the middle of the neck. Any way to fix this?