Coffee Appreciation

where is good to buy beans around Kew/Chiswick, so when i fail to buy coffee beans in central london i can buy a stop gap

otherwise of the beans sold in supermarkets are there any decent ones?

If you're South - Stockwell
West - Portobello Road
East - Mare Street
North - Camden

Any Portuguese shop will sell, what for me is, the best coffee beans money can buy (for a decent price, no pseudo-fancy shit).
I shit you not, don't doubt it, try it, please. It's a mix of Brazilian beans, the brand is called
**SICAL

**