Yeah, I think the issue for you in the UK is mainland Europe. There are just too many "standards" across the entire continent. It is not cost effective for them to produce UPS models for every one of those standards. Plus, your typical plugs tend to be physically much larger which would greatly limit the number of connections on the back of the UPS.
Here in the US (and Canada and most of Mexico) we have one 110-125VAC 3-prong standard. I have the
APC Back-UPS XS 1500 on this computer supporting my computer, 2 monitors and all my network gear. You can see by the rear image shot, it uses the
NEMA 5-15 connector, the same configuration used in all our standard home 110-125VAC wall outlets.
Note American homes are also typically wired for 240VAC high wattage appliances for our kitchen ovens/stove tops, electric clothes dryers, electric hot water heaters, electric forced air furnace systems, central AC, etc. Furnaces, hot water heaters and central AC units are typically hard wired. Note many homes use natural gas for the furnace and hot water (mine does). Ovens and dryers (if not using natural gas) use much larger connectors than you have over there (based on what I saw when I was stationed at RAF Mildenhall back in the 80s). There have been several standard 240-250VAC configurations used over the years but I believe the most common uses the
NEMA 10-30. But these are all pretty much industrial grade and you won't see these on UPS used for normal home consumer electronics (computers, TVs, table lamps, home theater sound, etc.) use.