Lancashire here ... depends, for solar gear I go to a single supplier that I have built up a relationship with over the years (www.onboardenergydirect.co.uk). For 12V stuff I tend to stick with 12voltplanet.co.uk. For most other stuff, amazon.co.uk or UK-based sellers on ebay.co.uk. I use froogle sometimes to identify sellers, usually just for price comparisons. I have in the past bought from aliexpress.com, but this is quite rare.