I vote black as well. And I wouldn't size up if the shoulders fit... these jackets are meant to look slightly shrunken and figure hugging.
I know the discount on the RO is a good deal, but just so you know, RO boutiques and other RO stockists discount his stuff every season. My friend got the gold metallic on sale last season and I got a black one with a slightly longer back on sale this season (there were around 10 other jackets there, including the leather + shearling one). If you check the NYC boutique or Luisaviaroma on the first day of sales, chances are you'll find a good deal there. It's better you hold out and wait for a RO you really like, than purchase one just because it's a bargain.