That has confirmed my original thoughts on the matter, so thanks👍
I’ve also received some info from an IT site and the Fire TV stick uses 0.2W in standby mode, and 3.8W when streaming. So I will be using the USB socket to power the Fire Stick when I rig up the Philips TV.
I’ve decided to order a Roku Express HD Media Streaming Player. I chose this brand as it’s takes less power form the USB outlet than the Firestick and as it’s from Amazon’s Choice listings, it’ll be easy returns should a fault develop …not bad for £20 delivered 
Roku Express | HD Streaming Media Player: Amazon.co.uk: Electronics & Photo
