After lots of thought and chat with MR peeps, I've developed a list of things I would like in a new reader. If anyone can think of a device which fits I would be infinitely grateful. 
1. The ability to load custom fonts.
2. Be able to create collections on a device 
which has never been connected to wifi. 
3. Must be able to sideload books (no wifi.)
4. Lots of appearance customisation of fonts, 
font size and weight, margins, line spacing etc
5. Blue light reduction would be a very nice 
feature to have, but I'm not convinced this 
technology has been refined, hence so many 
complaints. This may be why the latest 
Paperwhite doesn't have it. If there's a device 
without issues which uses it, that would be 
great. 
6. Leds not numbering between 12 and 14,  I 
have tridecaphobia. Unfortunately, the Kobo 
Clara HD fails here. 
7. Price under £150, but there's some 
movement here though definitely not over 
£200.
Thanks.