I have had a look at de-drm and also alternative e-book suppliers. The only e-book suppliers I can find (that seem legit) are Amazon (obviously), Rakuten (kobo) and e-books.com. I have searched all three for various books I would read and they are all coming out at around the same prices (maybe a couple of pence difference)
When I then consider I would either have to A) De-Drm and convert books or B) Buy a kobo e-reader (which don't seem to have as good a reviews online as Kindle,arent as easy to come by in the UK and are more expensive i.e the Kindle is £85 the cheapest Kobo available here is £120 to £140 and I already own a kindle to boot) I come to the conclusion it makes more sense to just stick with Kindle and Amazon, an annoying conclusion for sure but the most sensible.
Thank you everyone for your advice and suggestions and hopefully in the future there will be a viable and competitive alternative to Amazon for e-books (not holding my breath though!)