Have a look at Argos. I bought my fire stick there but not sure on the set top boxes. Failing that I do know of someone local who supplies and sets up the boxes but what you pay him is more expensive than doing it yourself but its not hard to setup if your a little IT literate.
You read correct. Kodi is the gateway to streaming pretty much anything. I installed Kodi on my laptop a few weeks back and so impressed with it have now bought a fire stick for it and connected it straight to my telly. Its the nuts !