Many of us are small - I, too, am Hobbit-sized!
Do look at the First and Twiggy sizes too for they aren't too large.
As for your City, it really depends on what your wardrobe is like and if you like to match or not. I bought a staple black First - also because I didn't have a black bag! - and then started adding on depending on what called out to me and also how it'd match my wardrobe.
Charcoal is a nice variation on the classic staple black, but BC (if you get a good one) can also be a classic in it's own way!
Hope this helps and good luck on deciding which to get!