Hi ChloeSS!
I voted for Chocolate primarily based on the leather choices. It also would be nice for you to have a darker, more neutral option within your collection. If the option for the Orange hadn't been in Epsom leather than I probably would have chosen the Orange, but I know you don't care for Epsom, so wouldn't want you to be unhappy. I was torn between the Chocolate and Orange, yet I felt that you would prefer the Togo leather of the Chocolate. But, I have an Orange 35cm. and it is a fun color...and Epsom would be a nice alternative to your other slouchier pieces...
Please let us know what you end up choosing!