09-04-2018, 09:14 AM
Just for point of reference, I like this PSU coupled with an adapter from microusb to barrel. It seems to provide the maximum supported power to the board. I've used the same on my RPI as well without the barrel adapter. I'm not sure if you can find it for the UK, however.
https://www.amazon.com/Optimum-Orbis-Des...wer+supply
https://www.amazon.com/Optimum-Orbis-Des...wer+supply