My vote goes to black ml flap. It's classic and can take you from day to evening. You already have a tote and the JMs serve as your day bags with a larger capacity. Beige flap would be good too but may not always work for evening purposes although you can use your black clutch.
Do you like the classic flap? Because so far, you have not purchased one and have bought other styles over the flap. What made you not buy the flap in the first place? If you had thought you would not get much use out of it, the reasons would probably stay the same. Hence, I would suggest the GST (provided you often use the tote that you already have haha). What size is your JM? If it's small or medium, it has the same capacity as the Jumbo. So if you would like a flap, the M/L would be my recommendation. Black and gold is classic Chanel.