For street photography in London you need a kit that is discrete enough to put your subject at ease (for reportage shots) and professional looking enough to be taken seriously (when asking permission for street portraits).
The GF2 is the core of my street photography kit because it's fast, light and discrete
The equipment I use for street photography is build around speed and ruggedness:
1. Panasonic Lumix DMC-GF2
2. Panasonic Lumix 14mm f/2.5
4. Hoya HMC Haze UV(C) – Filter
5. Panasonic DMW CGK3 Black leather case for GF2 by Panasonic
6. SanDisk Extreme HD 16 GB SDHC
7. Icebreaker Men’s Tech T Lite Superfine
The layers you wear when out taking photos are more important than you’d expect. You want to blend in, look safe, look sharp and be invisible. All at the same time. You also want to be warm enough or cool enough whatever the weather. Over the years I’ve settled on Merino t-shirts as the anchor in my street shooting kit.
Most of my merino t-shirts are from New Zealand brand Icebreaker
You can check out the full kit on Amazon at:
London Street Photo 
I also use the very good Panasonic black leather case when using the 14 mm; can you tell me if the new X 14-45 mm zoom lens fits in it ?