wowwww!! if i were in your shoes i would probably keep both bows!! but i do understand your dilemma with it being in the same season..
if it were me, i'd probably keep both but then regret keeping the amarena because i wouldn't use it as much..
the graphite is such an amazing colour that it will go with most outfits and you'll get more wear out of it.. if you're looking for an everyday bag, then i would definitely choose the graphite over the amarena, but if you're one of those people with "signature pieces" in their wardrobe and you're not going for practicality, i would go with the amarena..
but personally, i think the graphite is the better choice.. (then you can get something else that is amazing, since you can get something equally as nice for $1200, and wait for what comes out next season in the bows)
just my 2 cents! (or 10 since this reply was quite lengthy!)